JP5270106B2 - Polyamide resin composition and molded article comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition which excels in both properties of impact resistance and toughness including elongation and of mechanical properties such as tensile strength and welding strength, and furthermore excels in properties such as heat resistance, low water absorption, chemical resistance, and long-term heat resistance, and a molded article composed thereof. <P>SOLUTION: The polyamide resin composition is produced by kneading a polyamide (I) composed of a dicarboxylic acid unit containing 50-100 mol% terephthalic acid unit and a diamine unit containing 60-100 mol% a 6-18C aliphatic diamine unit and having a terminal amino group content ([NH<SB>2</SB>]) of 10 &mu;-eq/g and less than 60 &mu;-eq/g, a modified resin (II) modified with an unsaturated compound having a carboxyl group and/or an acid anhydride group, and at least one filler (III) selected from a fibrous filler and a needle filler at a specific ratio, and the molded article comprises the composition. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a polyamide resin composition excellent in heat resistance, rigidity, impact resistance, elongation, and the like, which is obtained by melt-kneading a specific polyamide, a modified resin, and a filler at a specific ratio, and a molded article comprising the same. .

  Aliphatic polyamides typified by nylon 6 and nylon 66 have excellent properties such as heat resistance, chemical resistance, rigidity, wear resistance, and moldability, and exhibit extremely high toughness in a moisture-absorbing state. For this reason, it has been used for a wide range of applications such as electric tools, general industrial parts, mechanical parts, electrical and electronic parts, automotive interior / exterior parts, engine room interior parts, automotive electrical parts, and sliding parts. However, aliphatic polyamides have problems such as not only dimensional changes due to water absorption and deterioration of physical properties but also inferior chemical resistance, and further improvement in performance has been desired.

  In response to such demands, various semi-aromatic polyamides (hereinafter, abbreviated as 6T polyamides) mainly composed of terephthalic acid and 1,6-hexanediamine have been proposed, and some have been put into practical use (patents). (Refer literature 1-3 etc.). However, a polyamide formed only from terephthalic acid and 1,6-hexanediamine has a melting point near 370 ° C., which exceeds the decomposition temperature of the polymer. Therefore, melt polymerization and melt molding are difficult and practical use is not possible. Has a low melting point in a practically usable temperature range, that is, about 280 to 320 ° C., by copolymerizing 30 to 40 mol% of a dicarboxylic acid component such as adipic acid or isophthalic acid or an aliphatic polyamide such as nylon 6. The current situation is that it is used in the form of Copolymerizing such a large amount of the third component (in some cases the fourth component) is certainly effective for lowering the melting point of the polymer, but on the other hand is accompanied by a decrease in crystallization speed and ultimate crystallinity. As a result, various physical properties such as rigidity at high temperatures, chemical resistance, and dimensional stability have been reduced, and productivity has been reduced as the molding cycle is extended. In addition, with respect to changes in physical properties such as dimensional stability due to water absorption, the introduction of aromatic groups, although somewhat improved compared to conventional aliphatic polyamides, has reached the level of substantial problem solving. It wasn't.

  As a polyamide resin that solves such problems and has further excellent performance in heat resistance, low water absorption and chemical resistance, terephthalic acid is a dicarboxylic acid unit, and 1,9-nonanediamine and / or 2-methyl-1 , 8-octanediamine is known as a semi-aromatic polyamide having a diamine unit (see Patent Documents 4 and 5). A molded body molded from this semi-aromatic polyamide has excellent low water absorption, and since the polyamide resin does not contain a third component having low heat resistance (in some cases, a fourth component), Excellent properties such as chemical resistance.

  By the way, for the purpose of improving mechanical properties such as strength, a resin composition in which a fibrous filler or an acicular filler is blended with a resin is known. However, a molded body molded from a semi-aromatic polyamide has a problem that the toughness such as impact resistance and elongation is lower than that of a molded body molded from an aliphatic polyamide. A semi-aromatic polyamide resin composition in which a fibrous filler or an acicular filler is blended with an aromatic polyamide has the same tendency.

  Various studies have already been attempted as means for improving the toughness in the polyamide resin composition. For example, it comprises a dicarboxylic acid component unit comprising a terephthalic acid component unit and a diamine component unit comprising an aliphatic diamine component unit and / or an alicyclic diamine component unit, and the amino group content is 0.04 to 0.2 meq / A resin composition comprising a specific semi-aromatic polyamide g and a specific polar group-containing polymer is known (see Patent Document 6). Further, it comprises a dicarboxylic acid component unit comprising a diamine component comprising a straight chain aliphatic diamine component unit having 8 to 10 carbon atoms and / or an aliphatic diamine component unit having a side chain, and a terephthalic acid component unit. A polyamide resin composition comprising a specific semi-aromatic polyamide having an amino group concentration of 10 to 150 mmol / kg and a specific graft-modified polymer is known (see Patent Document 7).

However, when a graft-modified polymer and a fibrous filler and / or an acicular filler are simply blended with a semi-aromatic polyamide, a fibrous filler and / or an acicular filler is blended. Nonetheless, the mechanical properties such as tensile strength deteriorate, or the mechanical properties such as tensile strength decrease rapidly when exposed to heating conditions for a long time, resulting in lack of long-term heat resistance. Sometimes occurred.
JP 60-158220 A Japanese Patent Laid-Open No. 3-7761 Japanese Patent Laid-Open No. 3-72565 JP 7-228769 A Japanese Patent Laid-Open No. 7-287772 Japanese Patent Laid-Open No. 5-117525 JP 2002-179910 A International Publication No. 01/81473 Pamphlet JP 2006-213798 A WO94 / 23433 pamphlet Japanese Patent No. 3761561

  The present invention is excellent in both properties such as toughness such as impact resistance and elongation, and mechanical properties such as tensile strength and weld strength, and also has heat resistance, low water absorption, chemical resistance, long-term heat resistance, etc. It aims at providing the polyamide resin composition which is excellent also in the characteristic of this, and a molded article consisting thereof.

As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have modified by a polyamide having a specific terminal amino group content, an unsaturated compound having a carboxyl group and / or an acid anhydride group. Modified polyamide resin, and at least one filler selected from a fibrous filler and an acicular filler, in a polyamide resin composition obtained by melting and kneading at a specific ratio, the terminal amino group of the polyamide used By setting the ratio (M _I / M _II ) of the total number of moles (M _I ) to the total number of moles (M _II ) of the carboxyl groups and acid anhydride groups of the modified resin, the above-mentioned purpose is achieved. The inventors have found that this can be achieved, and have further studied to complete the present invention.

That is, the present invention
[1] A dicarboxylic acid unit containing 50 to 100 mol% of a terephthalic acid unit, and 6 carbon atoms
A polyamide (I) having a terminal amino group content ([NH ₂ ]) of 10 μeq / g or more and 25 μeq / g or less , comprising diamine units containing 60 to 100 mol% of -18 aliphatic diamine units, A modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group, and at least one filler (III) selected from a fibrous filler and an acicular filler are added to a polyamide ( I), modified resin (II) and filler (III) in total 10
The polyamide (I) is 30 to 90 parts by mass, the modified resin (II) is 1 to 20 parts by mass, the filler (III) is 5 to 50 parts by mass with respect to 0 part by mass, and the terminal of the polyamide (I) The ratio (M _I / M _II ) of the total number of moles of amino groups (M _I ) to the total number of moles of carboxyl groups and acid anhydride groups (M _II ) of the modified resin ( _II ) is 2.0-9. A polyamide resin composition obtained by melt-kneading at a ratio of 0,
[2] The polyamide resin composition according to [1], wherein the aliphatic diamine unit having 6 to 18 carbon atoms is a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit,
[3] The modified resin (II) is at least one selected from the group consisting of polyolefin resins, polyester resins, polythioether resins, polynitrile resins, fluorine resins, and polyamide resins other than polyamide (I). The polyamide resin composition of [1] or [2], wherein the resin is modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group,
[4] The above [1] to [3], wherein the filler (III) is at least one selected from the following group:
[3] any polyamide resin composition,
Fibrous filler: glass fiber, wholly aromatic polyamide fiber Needle-shaped filler: potassium titanate whisker, aluminum borate whisker, calcium carbonate whisker, wollastonite whisker, zonotolite whisker [5] The above containing a conductive material [1] A polyamide resin composition according to any one of to [4],
[6] The polyamide resin composition according to [5], wherein the conductive material is at least one selected from the group consisting of carbon fiber, conductive carbon black, carbon fibril, and carbon nanotube.
[7] A molded article comprising the polyamide resin composition according to any one of [1] to [6] above,
[8] The molded article according to [7], which is a fuel tank for automobiles, a quick connector, a bearing retainer, a fuel tank for general-purpose equipment, a fuel cap, a fuel filler neck, a fuel sender module, a wheel cap, a fender, or a back door. .

  According to the present invention, it is excellent in both toughness such as impact resistance and elongation, and mechanical properties such as tensile strength and weld strength, and also has heat resistance, low water absorption, chemical resistance, and long-term heat resistance. A polyamide resin composition having excellent properties such as properties, and a molded article comprising the same are provided.

The following is a detailed description of the present invention.
The polyamide resin composition of the present invention comprises a dicarboxylic acid unit containing 50 to 100 mol% of terephthalic acid units and a diamine unit containing 60 to 100 mol% of aliphatic diamine units having 6 to 18 carbon atoms. Modified resin (II) modified with a polyamide (I) having an amino group content ([NH ₂ ]) of 10 μeq / g or more and 25 μeq / g or less , an unsaturated compound having a carboxyl group and / or an acid anhydride group ), And at least one filler (III) selected from a fibrous filler and an acicular filler.

  The dicarboxylic acid unit constituting the polyamide (I) contains 50 to 100 mol% of terephthalic acid units. When the content rate of the terephthalic acid unit in a dicarboxylic acid unit is less than 50 mol%, the heat resistance of the polyamide resin composition obtained will fall. The content of the terephthalic acid unit in the dicarboxylic acid unit is preferably in the range of 75 to 100 mol%, more preferably in the range of 90 to 100 mol%.

  The dicarboxylic acid unit constituting the polyamide (I) may contain other dicarboxylic acid units other than the terephthalic acid unit as long as it is 50 mol% or less. Examples of such other dicarboxylic acid units include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 2, Aliphatic dicarboxylic acids such as 2-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid; alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; isophthalic acid, 2, 6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, diphenylmethane-4,4 '-Dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-biphenyl Can be mentioned units derived from an aromatic dicarboxylic acid such as carboxylic acids, it can include one or more of them. The content of these other dicarboxylic acid units in the dicarboxylic acid unit is preferably 25 mol% or less, and more preferably 10 mol% or less. Furthermore, a unit derived from a polyvalent carboxylic acid such as trimellitic acid, trimesic acid, pyromellitic acid, and the like may be included within a range in which melt molding is possible.

  The diamine unit constituting the polyamide (I) contains 60 to 100 mol% of an aliphatic diamine unit having 6 to 18 carbon atoms. When polyamide (I) containing an aliphatic diamine unit having 6 to 18 carbon atoms in the above proportion is used, a polyamide resin composition excellent in toughness, slidability, heat resistance, moldability, low water absorption and lightness Is obtained. It is preferable that the content rate of a C6-C18 aliphatic diamine unit in a diamine unit exists in the range of 75-100 mol%, and the range of 90-100 mol% is more preferable.

  Examples of the aliphatic diamine unit having 6 to 18 carbon atoms include 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine. Linear aliphatic diamines such as 1,11-undecanediamine and 1,12-dodecanediamine; 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,2,4 -Branched chain such as trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine The unit derived from an aliphatic diamine etc. can be mentioned, The 1 type (s) or 2 or more types of these can be included.

  Since the aliphatic diamine unit having 6 to 18 carbon atoms can provide a polyamide resin composition that is more excellent in heat resistance, low water absorption and chemical resistance, 1,9-nonanediamine unit and / or 2-methyl- A 1,8-octanediamine unit is preferred. When the diamine unit includes both a 1,9-nonanediamine unit and a 2-methyl-1,8-octanediamine unit, the molar ratio of the 1,9-nonanediamine unit to the 2-methyl-1,8-octanediamine unit is 1,9-nonanediamine unit / 2-methyl-1,8-octanediamine unit = 95/5 to 50/50 is preferable, and 85/15 to 55/45 is more preferable.

  If the diamine unit which comprises polyamide (I) is 40 mol% or less, other diamine units other than a C6-C18 aliphatic diamine unit may be included. Examples of such other diamine units include aliphatic diamines such as ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, and 1,5-pentanediamine; cyclohexanediamine and methylcyclohexane. Alicyclic diamines such as diamine and isophoronediamine; p-phenylenediamine, m-phenylenediamine, xylylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylether, etc. The unit derived from the aromatic diamine or the like may be included, and one or more of these may be included. The content of these other diamine units in the diamine unit is preferably 25 mol% or less, and more preferably 10 mol% or less.

  Further, the polyamide (I) may contain an aminocarboxylic acid unit. Examples of the aminocarboxylic acid unit include units derived from lactams such as caprolactam and lauryllactam; aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. The content of the aminocarboxylic acid unit in the polyamide (I) is preferably 40 mol or less, more preferably 20 mol or less, with respect to 100 mol of all dicarboxylic acid units of the polyamide (I).

  In the polyamide (I), it is preferable that 10% or more of the end groups of the molecular chain are sealed with an end-capping agent. The ratio of the end groups of the molecular chain being sealed with the end-capping agent (end-capping rate) is more preferably 40% or more, and even more preferably 60% or more. When polyamide (I) having a terminal blocking rate of 10% or more is used, a polyamide resin composition having more excellent physical properties such as melt stability and hot water resistance can be obtained.

  The end capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with the amino group or carboxyl group at the end of the polyamide, but from the viewpoint of reactivity and stability of the capping end, Carboxylic acid or monoamine is preferable, and monocarboxylic acid is more preferable from the viewpoint of easy handling. In addition, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, and the like can also be used as the end-capping agent.

  The monocarboxylic acid used as the end-capping agent is not particularly limited as long as it has reactivity with an amino group. For example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, laurin Aliphatic monocarboxylic acids such as acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α-naphthalenecarboxylic acid , Β-naphthalene carboxylic acid, methyl naphthalene carboxylic acid, aromatic monocarboxylic acid such as phenyl acetic acid; any mixture thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearin, etc. Acid and benzoic acid are preferred.

  The monoamine used as the end-capping agent is not particularly limited as long as it has reactivity with a carboxyl group. For example, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearyl Aliphatic monoamines such as amine, dimethylamine, diethylamine, dipropylamine and dibutylamine; Cycloaliphatic monoamines such as cyclohexylamine and dicyclohexylamine; Aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; any mixtures thereof Can be mentioned. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferable from the viewpoints of reactivity, boiling point, stability of the sealing end, price, and the like.

The end capping rate of polyamide (I) was determined by measuring the number of carboxyl groups, amino groups and end groups blocked by end capping agent present in polyamide (I), respectively, by the following formula ( It can be determined according to 1). The number of each terminal group is preferably determined from the integral value of the characteristic signal corresponding to each terminal group by ¹ H-NMR in terms of accuracy and simplicity.
Terminal sealing rate (%) = [(A−B) / A] × 100 (1)
[Wherein A represents the total number of end groups of the polyamide (I) molecular chain (this is usually equal to twice the number of polyamide molecules), B is the remaining carboxyl end and amino Represents the total number of base ends. ]

  Polyamide (I) can be produced using any method known as a method for producing polyamide. For example, it can be produced by a solution polymerization method or an interfacial polymerization method using acid chloride and diamine as raw materials, a melt polymerization method using dicarboxylic acid and diamine as raw materials, a solid phase polymerization method, a melt extrusion polymerization method, or the like.

  In producing the polyamide (I), in addition to the above-mentioned end-capping agent, for example, phosphoric acid, phosphorous acid, hypophosphorous acid, salts or esters thereof can be added as a catalyst. Examples of the salt or ester include phosphoric acid, phosphorous acid or hypophosphorous acid, potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony, and the like. Salt with metal; ammonium salt of phosphoric acid, phosphorous acid or hypophosphorous acid; ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, decyl ester of phosphoric acid, phosphorous acid or hypophosphorous acid , Stearyl ester, phenyl ester and the like.

  The polyamide (I) preferably has an intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C. in the range of 0.6 to 2.0 dl / g, and 0.7 to 1.9 dl / g. The range of g is more preferable, and the range of 0.8 to 1.8 dl / g is more preferable. When the polyamide (I) having an intrinsic viscosity of less than 0.6 dl / g is used, there is a tendency that the mechanical properties of the resulting polyamide resin composition are lowered, and the polyamide (I) having an intrinsic viscosity of more than 2.0 dl / g is used. If it is used, the fluidity of the resulting polyamide resin composition tends to be lowered and the moldability tends to deteriorate.

Polyamide (I) has a terminal amino group content ([NH ₂ ]) of 10 μeq / g or more and 25 μeq / g or less . When the terminal amino group content ([NH ₂ ]) is less than 10 μeq / g, the compatibility between the polyamide and the modified resin (II) and the adhesion between the resin component and the filler (III) are insufficient. Further, when it exceeds 25 μeq / g, the long-term heat resistance and weld strength are reduced.

Polyamide (I) having a terminal amino group content ([NH ₂ ]) in the above-described range can be produced, for example, as follows.
First, a dicarboxylic acid, a diamine, and, if necessary, a catalyst and a terminal blocking 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 reaction raw material are represented by the following formula (2).
−0.5 ≦ [(Y−X) / Y] × 100 ≦ 2.0 (2)
Is satisfied, it is easy to produce a polyamide (I) having a terminal amino group content ([NH ₂ ]) of 10 μeq / g or more and less than 60 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] at 30 ° C. in concentrated sulfuric acid of 0.10 to 0.60 dl / g, and the degree of polymerization is further increased. Thus, the polyamide (I) used in the present invention can be obtained. When the intrinsic viscosity [η] of the prepolymer is in the range of 0.10 to 0.60 dl / g, there is little shift in the molar balance of the carboxyl group and amino group and a decrease in the polymerization rate at the stage of increasing the degree of polymerization, Furthermore, polyamide (I) having a small molecular weight distribution and excellent in various performances and moldability can be obtained. When the polymerization degree is increased by a solid phase polymerization method, it is preferably performed under reduced pressure or under an inert gas flow. If the polymerization temperature is in the range of 200 to 280 ° C., the polymerization rate is high, and the productivity is increased. And can effectively suppress coloring and gelation. When the polymerization degree is increased by a melt extruder, the polymerization temperature is preferably 370 ° C. or lower. When polymerization is performed under such conditions, polyamide is hardly decomposed and polyamide (I) having little deterioration. Is obtained.

Also, the terminal amino group content ([NH _2]) is also by combining a plurality of different kinds of polyamides, it may be polyamide (I) having a terminal amino group content of the desired ([NH _2]). In this case, the plurality of types of polyamides may be used by being mixed in advance before being melt-kneaded with the modified resin (II) and the filler (III), or may be used in a state where they are not previously mixed. That is, the polyamide resin composition of the present invention has a terminal amino group in a plurality of types of polyamides (I) having different terminal amino group contents ([NH ₂ ]), or in part or all of the plurality of types of polyamides. A plurality of types of polyamides in which the content ([NH ₂ ]) only does not satisfy the specification of the present invention, the proportion of terminal amino group content ([NH ₂ ]) in the whole of the plurality of polyamides satisfies the specification of the present invention. A polyamide resin composition obtained by melting and kneading these plural types of polyamides, modified resins (II) and fillers (III), including polyamide (I) as a whole when used.

  Examples of the unsaturated compound having a carboxyl group in the modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. And α, β-unsaturated carboxylic acids such as phthalic acid. Examples of the unsaturated compound having an acid anhydride group include dicarboxylic anhydrides having an α, β-unsaturated bond such as maleic anhydride, itaconic anhydride, and phthalic anhydride. The unsaturated compound having a carboxyl group and / or an acid anhydride group is preferably a dicarboxylic acid anhydride having an α, β-unsaturated bond, and more preferably maleic anhydride.

  The content of the carboxyl group and the acid anhydride group in the modified resin (II) is preferably in the range of 10 to 200 [mu] equivalent / g, and more preferably in the range of 50 to 100 [mu] equivalent / g. When the content of the functional group is less than 10 μequivalent / g, the impact resistance improvement effect may not be sufficient, while when it exceeds 200 μequivalent / g, the resulting polyamide resin composition The fluidity of the resin may decrease, and the moldability may decrease.

  Examples of the resin before modification in the modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group used in the present invention include, for example, low density polyethylene, medium density polyethylene, and high density polyethylene. , Polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer Polyolefin resins such as polymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, polybutadiene; polybutylene terephthalate, polyethylene terephthalate ,polyethylene Polyester resins such as phthalate, polybutylene naphthalate, polyethylene isophthalate, polyarylate, liquid crystal polyester; polyether resins such as polyacetal and polyphenylene oxide; polysulfone resins such as polysulfone and polyethersulfone; polyphenylene sulfide, polythioether sulfone, etc. Polythioether resins; Polyketone resins such as polyetheretherketone and polyallyletherketone; polyacrylonitrile, polymethacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, methacrylonitrile-butadiene- Polynitrile resins such as styrene copolymers; polymethacrylate resins such as polymethyl methacrylate and polyethyl methacrylate Polyvinyl acetate resin such as polyvinyl acetate; polyvinyl chloride resin such as polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, vinylidene chloride-methyl acrylate copolymer; cellulose acetate, cellulose butyrate, etc. Cellulose-based resins: polyvinylidene fluoride, polyvinyl fluoride, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetra Fluoro-resin such as fluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer; polycarbonate-based resin; polyimide-based resin such as thermoplastic polyimide, polyamideimide, and polyetherimide; Urethane resin; polyamide 6, polyamide 66, polyamide 46, polyamide 610, polyamide 612, polyamide 11, polyamide 12, polymetaxylylene adipamide (MXD6), polyhexamethylene terephthalamide (PA6T), polynonamethylene terephthalate Ramide (PA9T), polydecamethylene terephthalamide (PA10T), polydodecamethylene terephthalamide (PA12T), polybis (4-aminocyclohexyl) methane dodecamide (PACM12) and the polyamide raw material monomer forming these and / or the above Examples thereof include polyamide resins (however, other than polyamide (I)) such as copolymers using several polyamide raw material monomers. These resins may be used alone or in combination of two or more. As the modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group, the impact resistance, mechanical properties and heat resistance of the resulting molded product are further improved. At least one resin selected from the group consisting of resin based resins, polyester based resins, polythioether based resins, polynitrile based resins, fluorine based resins and polyamide based resins (excluding polyamide (I)). Preferably modified by an unsaturated compound having an anhydride group, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-propylene- Diene copolymer, polyarylate, polyphenyle At least one selected from the group consisting of sulfide, acrylonitrile-butadiene-styrene copolymer, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer was modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group. More preferably.

The filler (III) used in the present invention is at least one filler selected from a fibrous filler and an acicular filler. Examples of the fibrous filler include glass fiber, wholly aromatic polyamide fiber (for example, polyparaphenylene terephthalamide fiber, polymetaphenylene terephthalamide fiber, polyparaphenylene isophthalamide fiber, polymetaphenylene isophthalamide fiber, diaminodiphenyl ether). And fibers obtained from condensates of terephthalic acid and isophthalic acid), boron fibers, liquid crystal polyester fibers, and the like. Examples of the acicular filler include potassium titanate whisker, aluminum borate whisker, calcium carbonate whisker, wollastonite whisker, zonotlite whisker, calcium silicate whisker, magnesium sulfate whisker, zinc oxide whisker, sepiolite, and graphite whisker. Is mentioned. As the filler (III), one or more of these can be used. Among the above, the filler (III) is preferably at least one selected from the following group because the mechanical properties and heat resistance of the obtained molded product are further improved.
Fibrous filler: Glass fiber, wholly aromatic polyamide fiber Needle-filler: Potassium titanate whisker, Aluminum borate whisker, Calcium carbonate whisker, Wollastonite whisker, Zonotolite whisker

  The average length of the filler (III) used is preferably in the range of 1 μm to 20 mm from the viewpoint of maintaining good moldability and improving the mechanical properties and heat resistance of the obtained molded product. It is more preferably within the range of 10 mm, and even more preferably within the range of 10 μm to 5 mm. The aspect ratio of the filler (III) is preferably in the range of 5 to 2000, and more preferably in the range of 30 to 600.

  The filler (III) has been subjected to surface treatment since the adhesion to the matrix resin, particularly polyamide (I), is improved and the mechanical properties of the resulting polyamide resin composition are greatly improved. preferable. Examples of the surface treatment agent in the surface treatment include coupling agents such as a silane coupling agent, a titanium coupling agent, and an aluminate coupling agent, and a sizing agent. Preferred coupling agents include aminosilane, epoxy silane, methyltrimethoxysilane, methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, and vinyltrimethoxysilane. Examples of the sizing agent that can be suitably used include epoxy compounds, urethane compounds, carboxylic acid compounds, urethane / maleic acid-modified compounds, and urethane / amine-modified compounds. These surface treatment agents may be used alone or in combination of two or more. In particular, when a coupling agent and a sizing agent are used in combination, the adhesion between the filler (III) and the matrix resin, particularly the polyamide (I), is further improved, and the mechanical properties of the resulting polyamide resin composition are further improved. The surface-treated filler (III) has a mass loss when heated at 625 ± 20 ° C. for 10 minutes or more based on the total mass of the surface-treated filler (III), 0.01 to 8.0 mass. % Is preferable, and a range of 0.1 to 5.0% by mass is more preferable.

The polyamide resin composition of the present invention can contain a conductive material. By containing a conductive material, for example, it is possible to suppress the occurrence of electrostatic sparks when molded into fuel system parts, and the conductivity required when molding into automobile parts and further applying electrostatic coating. Can be granted. The conductive material in this specification is defined as having a volume resistivity of 10 ⁰ Ω · cm or less.

  Examples of the conductive material include carbon fibers, conductive carbon black, carbon fibrils, carbon nanotubes, metal fibers, metal powders, metal flakes, metal oxide powders, and metal-coated fibers. The conductive material is preferably at least one selected from the group consisting of carbon fibers, conductive carbon black, carbon fibrils, and carbon nanotubes because of its excellent balance between the effect of imparting property and the reinforcing effect. In the present specification, the filler (III) may also serve as a conductive material. For example, carbon fibers, carbon fibrils, carbon nanotubes, metal fibers, metal-coated fibers, and the like may be conductive materials as well as fillers (III).

  The carbon fiber may be either pitch-based or PAN-based carbon fiber, but PAN-based carbon fiber is more preferable in terms of elastic modulus and impact resistance. The average fiber length of the carbon fibers is preferably in the range of 1 to 20 mm in the state before melt kneading from the viewpoint of maintaining good moldability and improving the mechanical properties and heat resistance of the obtained molded product. A range of 3 to 10 mm is more preferable, and a range of 5 to 8 mm is more preferable. The aspect ratio of the carbon fiber is preferably in the range of 100 to 5000, and more preferably in the range of 300 to 2000.

  As said conductive carbon black, the carbon black etc. which are described as carbon black for electroconductivity in patent document 8 or 9 can be used, for example. Commercially available conductive carbon black can also be used. Ketjen Black EC600JD and EC300J available from Ketjen Black International Co., Ltd .; Vulcan XC-72 and XC-305 available from Cabot Corporation; PrintexXE2B available from Degussa, Inc .; # 5500 available from Tokai Carbon Co., Ltd., # 4500; # 5400B available from Mitsubishi Chemical Corporation, etc. can be used.

As said carbon fibril, the fine carbon fiber etc. which are described in patent document 10 can be used. Commercially available carbon fibrils can also be used, and BN fibrils available from Hyperion Catalysis International can be used.
Moreover, as a carbon nanotube, the multilayer carbon nanotube etc. which are described in patent document 11 can be used.

  The content of the conductive material is preferably in the range of 0.1 to 30% by mass, preferably 0.2 to 25% by mass with respect to the polyamide resin composition, because of the excellent balance between conductivity and mechanical properties. % Is more preferable, and 0.3 to 20% by mass is more preferable.

If necessary, the polyamide resin composition of the present invention comprises a resin other than the polyamide (I) and the modified resin (II), a filler (III) and a filler other than the conductive material, a crystal nucleating agent, copper Stabilizers, hindered phenol antioxidants, hindered amine antioxidants, phosphorus antioxidants, thio antioxidants, colorants, UV absorbers, light stabilizers, antistatic agents, plasticizers, lubricants, Other components such as a flame retardant and a flame retardant aid may be included.
Examples of other fillers include powdery fillers such as calcium carbonate, silica, silica alumina, alumina, titanium dioxide, and molybdenum disulfide; flakes such as hydrotalcite, glass flakes, mica, clay, montmorillonite, and kaolin A filler etc. are mentioned.
The crystal nucleating agent is not particularly limited as long as it is generally used as a crystal nucleating agent for polyamide resin. For example, talc, silica, calcium stearate, aluminum stearate, barium stearate, zinc stearate, these And any mixture thereof. Among these, talc is preferable because it has a large effect of increasing the crystallization speed of the polyamide resin. The crystal nucleating agent may be treated with a silane coupler, a titanium coupler or the like for the purpose of improving compatibility with the polyamide resin.
The content of these other components in the polyamide resin composition is preferably 50% by mass or less, more preferably 20% by mass or less, and further preferably 5% by mass or less.

  The polyamide resin composition of the present invention comprises the above polyamide (I), a modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group, a filler (III), and, if necessary. It can be manufactured by melting and kneading the conductive material and the other components described above. Polyamide (I), modified resin (II) and filler (III) are used in a proportion of 100 parts by mass of polyamide (I), modified resin (II) and filler (III). 30 to 90 parts by mass, modified resin (II) 1 to 20 parts by mass, filler (III) 5 to 50 parts by mass, polyamide (I) 45 to 85 parts by mass, and modified resin (II) 3-15 parts by mass, filler (III) is preferably 10-40 parts by mass, polyamide (I) is 60-80 parts by mass, modified resin (II) is 5-10 parts by mass, filler (III ) Is more preferably 15 to 35 parts by mass, polyamide (I) is 60 to 75 parts by mass, modified resin (II) is 5 to 8 parts by mass, and filler (III) is 20 to 35 parts by mass. More preferably.

Further, the total moles of the terminal amino groups of the polyamide used _(I) (M I) and the modified resin (II) the total number of moles of carboxyl groups and acid anhydride groups with the (M _II) the ratio of (M _I / M _II ) needs to be 2.0 to 9.0. When the ratio (M _I / M _II ) is less than 2.0, the mechanical properties of the resulting polyamide resin composition are inferior in general, and when it exceeds 9.0, the weld strength decreases. . The decrease in weld strength is considered to occur when polyamide (I) is incorporated into the modified resin (II) due to excessive compatibilization and the apparent volume fraction of the modified resin (II) increases. From the viewpoint of improving physical properties in general mechanical properties including weld strength, the ratio (M _I / M _II ) is preferably in the range of 2.2 to 8.0, preferably 3.0 to 6 Within the range of 0.0 is more preferable.

  As the melt-kneading method, conventionally known methods can be employed, and for example, it can be carried out using a kneader such as a single-screw extruder, a twin-screw extruder, a kneader, or a Banbury mixer. There are no particular restrictions on the type of apparatus or melt-kneading conditions used at that time. For example, the polyamide resin composition of the present invention is obtained by kneading at a temperature in the range of about 280 to 350 ° C. for 1 to 30 minutes. be able to. In the present specification, the melt-kneading means kneading performed under the condition that at least the polyamide (I) is melted.

  When the polyamide resin composition of the present invention is obtained by melt-kneading, the polyamide (I) and the modified resin (II) are melt-kneaded in an extruder or the like, and the filler (III) is added in the extruder or the like. Side feed from the downstream supply port is preferred because a polyamide resin composition having better mechanical properties can be obtained.

  In particular, when a conductive material is used, polyamide (I), modified resin is used by using a co-rotating twin-screw extruder (a) provided with at least one upstream supply port and one downstream supply port. A method in which (II) and a conductive material are mixed in advance, and are collectively introduced into the upstream supply port and melt-kneaded, and a filler (III) other than the conductive material is introduced from the downstream supply port and melt-kneaded [kneading method A] A master batch is prepared by previously mixing a part or all of the melt of polyamide (I) and a conductive material, and the master batch, the remainder of polyamide (I) and the modified resin (II) are mixed. The melt-kneading is performed by charging into the upstream supply port of the same-direction rotating twin-screw extruder (a), and the filler (III) other than the conductive material is charged through the downstream supply port and melt-kneaded [ Kneading method B], polyamide (I) and conductive material are mixed in advance, A supply port, a midstream portion supply port, and a downstream portion supply port are each put into an upstream portion supply port of a co-rotating twin-screw extruder (b) having one or more locations, melted and kneaded. (II) is charged and melt-kneaded, and a filler (III) other than a conductive material is charged from the downstream supply port and melt-kneaded [kneading method C], part or all of the polyamide (I) in advance The melt and the conductive material are mixed to prepare a master batch, the master batch and the remainder of the polyamide (I) are mixed, and the upstream supply port of the co-rotating twin-screw extruder (b) And then melted and kneaded, the modified resin (II) is charged from the midstream supply port and melted and kneaded, and the filler (III) other than the conductive material is charged from the downstream supply port and melt kneaded [ Kneading method D], part or all of polyamide (I) and modified resin ( II) is mixed in advance, and is charged into the upstream supply port of the above-mentioned co-rotating twin screw extruder (b) and melted and kneaded, and the conductive material and the remainder of the polyamide (I) are charged from the midstream supply port. It is preferable to employ a method [kneading method E] in which melt-kneading is performed, and filler (III) other than the conductive material is further introduced from the downstream supply port to melt-knead.

  The thermoplastic resin composition of the present invention, such as injection molding, extrusion molding, press molding, blow molding, calendar molding, casting molding, etc., depending on the type, application, shape, etc. of the target molded product Various molded products can be manufactured by molding by a molding method generally used for products. A molding method combining the above molding methods can also be employed. Furthermore, the polyamide resin composition of the present invention and other polymers can be composite-molded.

  Examples of molded articles made of the polyamide resin composition of the present invention include, for example, radiator grills, rear spoilers, wheel covers, wheel caps, cowl vent grills, air outlet louvers, air scoops, food bulges, fenders, back doors, etc. Automotive exterior parts: cylinder head cover, engine mount, air intake manifold, throttle body, air intake pipe, radiator tank, radiator support, water pump inlet, water pump outlet, thermostat housing, cooling fan, fan Shroud, oil pan, oil filter housing, oil filler cap, oil level gauge, timing belt, timing belt cover Engine compartment parts for automobiles such as engine covers; fuel caps, fuel filler tubes, fuel tanks for automobiles, fuel sender modules, fuel cutoff valves, quick connectors, canisters, fuel delivery pipes, fuel filler necks, etc. Automotive fuel system parts; Automobile drive system parts such as shift levers and housings; Propeller shafts; Automobile chassis parts such as stabilizer bars and linkage rods; Window regulators, door locks, door handles, outside door mirrors and stays , Accelerator pedals, pedal modules, seal rings, bearings, bearing retainers, gears, actuators and other functional parts for automobiles; wire harnesses, connectors, relays Automotive electronics parts such as locks, sensor housings, encapsulation, ignition coils, distributor caps, etc .; fuel system parts for general equipment such as fuel tanks for general equipment (mowers, lawn mowers, chainsaws, etc.); Examples include electrical and electronic parts such as connectors and LED reflectors. The polyamide resin composition of the present invention is excellent in both properties such as toughness such as impact resistance and elongation and mechanical properties such as tensile strength. Excellent in properties such as heat resistance, low water absorption, chemical resistance, and long-term heat resistance, especially fuel tanks for automobiles, quick connectors, bearing retainers, fuel tanks for general equipment, fuel caps, fuel filler necks, Fuel sender module, wheel cap, fender or Can be preferably used as a back door.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Terminal amino group content ([NH ₂ ]), method for producing molded product (test piece), tensile strength, tensile elongation at break, weld strength, impact resistance (Charpy impact strength with notch) and long-term heat resistance The evaluation method is shown below.

Terminal amino group content ([NH ₂ ])
1 g of semi-aromatic polyamide resin was dissolved in 35 mL of phenol, and 2 mL of methanol was mixed to prepare a sample solution. Titration was performed using thymol blue as an indicator and an aqueous 0.01 N HCl solution, and the terminal amino group content ([NH ₂ ], unit: μ equivalent / g) was measured.

Production of molded product (test piece) Using an injection molding machine (clamping force: 80 tons, screw diameter: φ32 mm) manufactured by Toshiba Machine Co., Ltd. under conditions of a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C., An ISO multipurpose specimen A-type dumbbell was prepared using a T-runner mold and used for evaluation of tensile elongation at break, tensile strength and long-term heat resistance. Further, a rectangular parallelepiped test piece (dimension: length × width × thickness = 80 mm × 10 mm × 4 mm) was cut out from the ISO multipurpose test piece A-type dumbbell and used for evaluation of impact resistance. In addition, an ISO multipurpose test piece A-type weld dumbbell was produced using a double T-runner mold and used for evaluation of weld strength. Furthermore, a rectangular parallelepiped test piece (dimensions: length × width × thickness = 80 mm × 50 mm × 3 mm) was prepared for conductivity evaluation.

Evaluation of impact resistance Notches at 23 ° C. and −40 ° C. using a Charpy impact tester (manufactured by Toyo Seiki Seisakusyo Co., Ltd.) according to ISO 179 / 1eA using the test piece prepared by the above method. The Charpy impact value was measured to evaluate the impact resistance.

Evaluation of tensile elongation at break, tensile strength and weld strength Using the test piece prepared by the above method, using Autograph (manufactured by Shimadzu Corporation) according to ISO 527-1, tensile at 23 ° C Elongation at break and tensile strength (tensile yield strength) were measured. Further, the weld strength (weld yield strength) was measured using a weld dumbbell in the same manner.

Evaluation of long-term heat resistance Using the test piece prepared by the above method, heat treatment was performed at 170 ° C. for 1000 hours in a hot air dryer. Then, according to ISO527-1, the tensile strength (tensile yield strength) before and behind heat processing in 23 degreeC was measured using the autograph (made by Shimadzu Corporation). Then, the ratio (%) of “tensile strength of the test piece after heat treatment” with respect to “tensile strength of the test piece before heat treatment” was determined and defined as long-term heat resistance (%).

Conductivity evaluation Using the test piece prepared by the above method, according to JIS K 7194, using a low resistivity meter (Loresta GP, manufactured by Mitsubishi Chemical Corporation), the test piece center was applied at a voltage of 90V. The surface resistivity at one point of the part was measured. The measurement was performed using five different test pieces, and the conductivity was evaluated using the addition average value as the surface resistivity (average value).

[Reference Example 1] Production of semi-aromatic polyamide (PA9T-1) 4537.7 g (27.3 mol) of terephthalic acid, mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [former / latter = 80/20 (molar ratio)] 4496.5 g (28.4 mol), benzoic acid 84.4 g (0.69 mol), sodium hypophosphite monohydrate 9.12 g (based on the total mass of the raw materials) 0.1 mass%) and 2.5 liters of distilled water were placed in an autoclave having an internal volume of 20 liters and purged with nitrogen. The mixture was stirred at 100 ° C. for 30 minutes, and the temperature inside the autoclave was increased to 220 ° C. over 2 hours. At this time, the pressure inside the autoclave was increased to 2 MPa. The reaction was continued as it was for 2 hours, then 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 keeping the pressure at 2 MPa. Next, the pressure was reduced to 1 MPa over 30 minutes, and the reaction was further continued for 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.15 dl / g. This was dried at 100 ° C. under reduced pressure for 12 hours and pulverized to a particle size of 2 mm or less. This was solid-phase polymerized at 230 ° C. and 13 Pa (0.1 mmHg) for 10 hours. The melting point was 300 ° C., the intrinsic viscosity [η] was 1.17 dl / g, and the terminal amino group content ([NH ₂ ]) was 90 μeq. A white polyamide having a terminal carboxyl group content of 4 μequivalent / g and a terminal blocking rate of 83% was obtained. This polyamide is abbreviated as “PA9T-1”.

[Reference Example 2] Production of semi-aromatic polyamide (PA9T-2) 4601.0 g (27.7 mol) of terephthalic acid, mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [former / latter = 80/20 (molar ratio)] 4432.1 g (28.0 mol), benzoic acid 116.0 g (0.95 mol), sodium hypophosphite monohydrate 9.12 g (based on the total mass of the raw materials) 0.1 mass%) and 2.5 liters of distilled water were placed in an autoclave having an internal volume of 20 liters and purged with nitrogen. The mixture was stirred at 100 ° C. for 30 minutes, and the temperature inside the autoclave was increased to 220 ° C. over 2 hours. At this time, the pressure inside the autoclave was increased to 2 MPa. The reaction was continued as it was for 2 hours, then 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 keeping the pressure at 2 MPa. Next, the pressure was reduced to 1 MPa over 30 minutes and the reaction was further continued for 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.17 dl / g. This was dried at 100 ° C. under reduced pressure for 12 hours and pulverized to a particle size of 2 mm or less. This was solid-phase polymerized at 230 ° C. and 13 Pa (0.1 mmHg) for 10 hours. The melting point was 300 ° C., the intrinsic viscosity [η] was 1.22 dl / g, and the terminal amino group content ([NH ₂ ]) was 8 μequivalent. A white polyamide having a terminal carboxyl group content of 65 μequivalent / g and a terminal blocking rate of 85% was obtained. This polyamide is abbreviated as “PA9T-2”.

  In the following examples and comparative examples, the following polyamide, modified resin (II), filler (III) and conductive material were used.

Polyamide PA9T-2 produced in Reference Examples 1 and 2 above was used as it was, or PA9T-1 and PA9T-2 were used in the proportions described in Table 1 or 2 below.

Modified resin (II)
EBR-1: Maleic anhydride-modified ethylene-butene copolymer (“Tafmer MH7020” manufactured by Mitsui Chemicals, content of acid anhydride group: 100 μeq / g)
EBR-2: Maleic anhydride-modified ethylene-butene copolymer (Mitsui Chemicals “Toughmer MH7010”, content of acid anhydride group: 50 μeq / g)
The content of acid anhydride groups in the modified resin (II) was determined by using phenolphthalein using a sample solution prepared by dissolving 5 g of the pellet of the modified resin (II) in 170 mL of toluene and adding 30 mL of ethanol. Was determined by neutralization titration with a 0.1 N KOH ethanol solution.

Filler (III)
GF: Glass fiber (“CS03JA-FT2A” manufactured by Owens Corning)
Conductive material (filler (III))
CF: carbon fiber (“TENAX HTA-C6-NR” manufactured by Toho Tenax Co., Ltd., volume resistivity: 1.5 × 10 ⁻³ Ω · cm, average fiber length before melt kneading: 6 mm, aspect ratio: 860)

<Examples 1-4 and Comparative Examples 1-9>
After premixing the polyamide, the modified resin (II) modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group, and a conductive material in the proportions shown in Table 1 or 2, the twin screw extruder ( Supplied to “BTN-32” manufactured by Plastic Engineering Laboratory Co., Ltd., melted and kneaded at a cylinder temperature of 320 ° C., supplied with filler (III) using a side feeder, extruded, cooled and cut. A pellet-shaped polyamide resin composition was produced. Various physical property evaluations were performed using the obtained polyamide resin composition. The results are shown in Tables 1 and 2 below.

  From Table 1, the polyamide resin compositions of Examples 1 to 4 having each requirement specified in the present invention are toughness such as impact resistance and tensile elongation at break, mechanical properties such as tensile strength and weld strength, and long-term. It turns out that it is excellent in heat resistance.

On the other hand, the polyamide resin composition obtained in Comparative Example 1 has the total number of moles of terminal amino groups (M _I ) of polyamide (I) and the total number of moles of carboxyl groups and acid anhydride groups of the modified resin (II). for (M _II) the ratio of (M I _/ M _II) is too low, poor mechanical properties such as tensile strength, the tensile elongation at break was also reduced.

The polyamide resin composition obtained in Comparative Example 2 is composed of the total number of moles of terminal amino groups (M _I ) of polyamide (I) and the total number of moles of carboxyl groups and acid anhydride groups of the modified resin (II) (M _II )) (M _I / M _II ) was too high, resulting in poor weld strength and long-term heat resistance.

The polyamide resin composition obtained in Comparative Example 3 had a low terminal amino group content ([NH ₂ ]) of the polyamide, so that the tensile elongation at break was inferior and the mechanical properties such as tensile strength were also lowered.

The polyamide resin composition obtained in Comparative Example 4 was inferior in mechanical properties such as weld strength and long-term heat resistance because the terminal amino group content ([NH ₂ ]) of the polyamide was too high.

The polyamide resin composition obtained by Comparative Example 5 has a polyamide terminal amino group content ([NH ₂ ]) that is too low, and the total number of moles of the terminal amino groups of the polyamide (M _I ) and the modified resin (II). Since the ratio (M _I / M _II ) to the total number of moles of carboxyl groups and acid anhydride groups (M _II / M _II ) of the resin is too low, the mechanical properties such as tensile strength and weld strength and tensile elongation at break were inferior .

The polyamide resin composition obtained in Comparative Example 6 has a polyamide terminal amino group content ([NH ₂ ]) that is too high, and the total number of moles of the terminal amino groups of the polyamide (M _I ) and the modified resin (II). Since the ratio (M _I / M _II ) with respect to the total number of moles (M _II ) of the carboxyl groups and acid anhydride groups possessed by M was too high, the long-term heat resistance was poor and the weld strength was also reduced.

  Since the polyamide resin composition obtained in Comparative Example 7 did not contain the filler (III), the mechanical properties such as tensile strength and impact resistance were remarkably inferior, and the long-term heat resistance was also lowered.

  Since the polyamide resin composition obtained by Comparative Example 8 did not contain the modified resin (II), it was remarkably inferior in impact resistance.

The polyamide resin composition obtained in Comparative Example 9 was inferior in mechanical properties such as weld strength and long-term heat resistance because the terminal amino group content ([NH ₂ ]) of the polyamide was too high.

  The polyamide resin composition of the present invention is excellent in both properties such as toughness such as impact resistance and elongation, and mechanical properties such as tensile strength and weld strength, and also has heat resistance, low water absorption and chemical resistance. Because it has excellent characteristics such as long-term heat resistance, automotive fuel tanks, quick connectors, bearing retainers, fuel tanks for general equipment, fuel caps, fuel filler necks, fuel sender modules, wheel caps, fenders, and back doors It is useful as a material constituting various types of molded articles.

Claims (8)

It consists of a dicarboxylic acid unit containing a terephthalic acid unit from 50 to 100 mol%, and diamine units containing 60 to 100 mol% of aliphatic diamine units having from 6 to 18 carbon atoms, terminal amino group content _([NH 2]) polyamide (I), modified modified resin by an unsaturated compound having a carboxyl group and / or an acid anhydride group (II), as well as fibrous fillers and needle but is below 10μ equivalents / g or more 25 mu eq / g At least one filler (III) selected from the fillers in the form of polyamide (I) is 30 to 90 with respect to 100 parts by mass in total of polyamide (I), modified resin (II) and filler (III). 1 to 20 parts by mass of the modified resin (II), 5 to 50 parts by mass of the filler (III), and the total number of moles (M _I ) of terminal amino groups of the polyamide ( _I ) and the modified resin (II) ) Total number of moles of carboxyl groups and acid anhydride groups (M _II) and the ratio _(M I / _{M II)} is a polyamide resin composition obtained by melt-kneading so that the ratio of 2.0 to 9.0.   The polyamide resin composition according to claim 1, wherein the aliphatic diamine unit having 6 to 18 carbon atoms is a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit.   The modified resin (II) is at least one resin selected from the group consisting of polyolefin resins, polyester resins, polythioether resins, polynitrile resins, fluorine resins, and polyamide resins other than polyamide (I). The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin composition is modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group. The polyamide resin composition according to any one of claims 1 to 3, wherein the filler (III) is at least one selected from the following group.
Fibrous filler: Glass fiber, wholly aromatic polyamide fiber Needle-filler: Potassium titanate whisker, Aluminum borate whisker, Calcium carbonate whisker, Wollastonite whisker, Zonotolite whisker   The polyamide resin composition according to any one of claims 1 to 4, comprising a conductive material.   The polyamide resin composition according to claim 5, wherein the conductive material is at least one selected from the group consisting of carbon fibers, conductive carbon black, carbon fibrils, and carbon nanotubes.   The molded article which consists of a polyamide resin composition in any one of Claims 1-6.   The molded article according to claim 7, which is a fuel tank for automobiles, a quick connector, a bearing retainer, a fuel tank for general-purpose equipment, a fuel cap, a fuel filler neck, a fuel sender module, a wheel cap, a fender or a back door.