JP2019001916A - Polyamide resin composition - Google Patents

Abstract

To provide a polyamide resin composition excellent in low-temperature impact resistance and flowability.SOLUTION: The polyamide resin composition is provided that includes (A) a polyamide resin, (B) an ethylene-α-olefin copolymer which has an MFR of 20-50 g/10 minutes when measured at 190°C and a load of 2.16 kg in accordance with ASTM D 1238, and (C) an ethylene-α-olefin copolymer which is graft modified with an unsaturated carboxylic acid or its derivative, and has an MFR of 0.1-10 g/10 minutes when measured at 190°C and a load of 2.16 kg in accordance with ASTM D 1238.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition excellent in impact resistance, particularly impact resistance at low temperatures and fluidity.

  Polyamide resins have excellent mechanical properties (such as mechanical strength, rigidity and impact resistance), heat resistance, and chemical resistance, so they are used in clothing, industrial materials, automobiles, electrical and electronic parts, and other industrial products. It is used in various industrial fields.

  However, since polyamide resins are not sufficient in performance such as impact properties, particularly impact properties at low temperatures, various studies have been made for improvement.

  For example, a method of blending an ethylene / α-olefin copolymer grafted with an unsaturated carboxylic acid into a polyamide resin has been proposed (see, for example, Patent Documents 1 and 2). A method of blending a graft-modified ethylene / 1-butene copolymer with a polyamide resin has also been proposed (for example, Patent Document 3).

Japanese Patent Publication No.55-44108 JP-A-55-962 JP-A-7-97503

In recent years, good fluidity has been demanded as automobile parts have become thinner and electric and electronic parts have become smaller and more precise.
However, the conventional technology is not sufficient in terms of improving fluidity while maintaining impact resistance.

  An object of the present invention is to provide a polyamide resin composition excellent in low-temperature impact resistance and fluidity, which is suitable for automobile parts, small precision parts and the like.

  As a result of intensive studies to solve the above problems, the present inventors have made graft modification with an ethylene / α-olefin copolymer and an α, β-unsaturated carboxylic acid or derivative thereof contained in the polyamide resin composition. It was found that the obtained ethylene / α-olefin copolymer is effective for obtaining a polyamide resin composition excellent in these characteristics when the MFR measured by a predetermined method is within a predetermined range. Reached.

That is, the polyamide resin composition of the present invention is
(A) a polyamide resin, (B) an ethylene / α-olefin copolymer having an MFR of 20 to 50 g / 10 min measured at 190 ° C. under a load of 2.16 kg according to ASTM D1238, and (C) 190 according to ASTM D1238. And an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or derivative thereof having an MFR of 0.1 to 10 g / 10 min measured at 2 ° C. and a load of 2.16 kg.

The density of the component (B) and / or the component (C) is preferably 0.85 to 0.89 g / cm ³ .
The ethylene / α-olefin copolymer of the component (B) and / or the component (C) is preferably a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

The unsaturated carboxylic acid or derivative thereof as component (C) is maleic anhydride and preferably has a modification rate of 0.1 to 3% by mass.
The component (A) preferably has a viscosity number of 80 to 150 ml / g measured with sulfuric acid having a mass fraction of 96% in accordance with ISO 307.

It is preferable that (A) component is 51-95 mass%, (B) component is 2-45 mass%, and (C) component is 2-45 mass% with respect to 100 mass% of polyamide resin compositions.
It is preferable that (C) component is 20-60 mass% with respect to a total of 100 mass% of (B) component and (C) component.

 The method for improving the impact resistance at 0 ° C. or lower of the present invention uses the polyamide resin composition of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the polyamide resin composition excellent in low temperature impact resistance and fluidity | liquidity can be provided.

The present invention will be specifically described below.
First, each component that can be used in the present invention will be described in detail.

[(A) Polyamide resin (component (A))]
“Polyamide” means a polymer compound having a —CO—NH— (amide) bond in the main chain. The polyamide used in the present invention is not particularly limited. For example, (a) polyamide obtained by ring-opening polymerization of lactam, (b) polyamide obtained by self-condensation of ω-aminocarboxylic acid, (c) diamine and Examples thereof include polyamides obtained by condensing dicarboxylic acids, and copolymers thereof. Polyamide may be used alone or as a mixture of two or more. Hereinafter, the raw material of the polyamide resin used in the present invention will be described.

  Although it does not specifically limit as a lactam used as the raw material of said (a) polyamide, For example, a pyrrolidone, a caprolactam, an undecaractam, a dodecaractam, etc. are mentioned.

  Moreover, it does not specifically limit as (omega) omega-aminocarboxylic acid used as the raw material of said (b) polyamide resin, For example, the omega-amino fatty acid etc. which are the ring-opening compounds by the said lactam with water are mentioned. The (a) polyamide and (b) polyamide may each be a condensation product of two or more lactams or ω-aminocarboxylic acids.

  Subsequently, the diamine (monomer) used as the raw material for the above (c) polyamide is not particularly limited. For example, a linear aliphatic diamine such as hexamethylene diamine or pentamethylene diamine; 2-methylpentane diamine; And branched aliphatic diamines such as 2-ethylhexamethylenediamine; aromatic diamines such as p-phenylenediamine and m-phenylenediamine; and alicyclic diamines such as cyclohexanediamine, cyclopentanediamine, and cyclooctanediamine. It is done.

On the other hand, the dicarboxylic acid (monomer) used as the raw material for the polyamide (c) is not particularly limited. For example, aliphatic dicarboxylic acids such as adipic acid, pimelic acid and sebacic acid; phthalic acid and isophthalic acid Aromatic dicarboxylic acids; cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid and the like.
The (c) polyamide may be a single type or a combination of two or more types of diamines and dicarboxylic acids.

  The polyamide is not particularly limited. For example, polyamide 4 (polyα-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene). Adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 410 (polytetramethylene sebacamide), polyamide 412 (polytetramethylene dodecamide), polyamide 610 (Polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 1010 (polydecamethylene sebacamide), polyamide 1012 (polydecamethylene dodecamide), polyamide 6T (polyhexa Chi terephthalamide), polyamide 9T (poly nonane terephthalamide), and polyamide 6I (polyhexamethylene isophthalamide), and the like copolymerized polyamides containing them as a component.

  Although it does not specifically limit as a terminal group of the polyamide used by this invention, Generally an amino group or a carboxyl group exists. The ratio of the amount of amino end groups to the total amount of amino end groups and carboxyl end groups in the polyamide used in the present invention [amino end group amount / (amino end group amount + carboxyl end group amount)] is 0.2 or more and 1 Is preferably less than 0.5, more preferably from 0.2 to 1.0, and even more preferably from 0.2 to 0.6. When the ratio of the amount of terminal groups is within the above range, the color tone, mechanical strength, and vibration fatigue resistance of the molded product obtained from the polyamide resin composition tend to be more excellent.

  The amount of amino end groups of the polyamide is preferably 10 to 100 μmol / g, more preferably 15 to 80 μmol / g, and further preferably 30 to 80 μmol / g. When the amino terminal group amount is within the above range, the impact resistance of the polyamide resin composition tends to be more excellent.

Here, as an example of the measuring method of the amount of amino terminal groups and the amount of carboxyl terminal groups in this specification, < ¹ > H-NMR method and titration method are mentioned. ^{In the 1} H-NMR method, it can be determined by the integral value of the characteristic signal corresponding to each terminal group. In the titration method, for the amino end group, a method of titrating a polyamide resin phenol solution with 0.1N hydrochloric acid, for the carboxyl end group, a method of titrating a polyamide resin benzyl alcohol solution with 0.1N sodium hydroxide, etc. Is mentioned.

  Furthermore, as a method for adjusting the concentration of the end groups of the polyamide used in the present invention, a known method can be used. Although it does not specifically limit as an adjusting method, For example, the method of using a terminal adjusting agent is mentioned. As a specific example, adding one or more terminal regulators selected from the group consisting of a monoamine compound, a diamine compound, a monocarboxylic acid compound, and a dicarboxylic acid compound so as to have a predetermined terminal concentration during polymerization of polyamide. Is mentioned. The timing of adding the terminal adjuster to the solvent is not particularly limited as long as it functions as a terminal adjuster. For example, the above-described polyamide raw material may be added to the solvent.

  The monoamine compound is not particularly limited, but examples thereof 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. Of these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline are preferable from the viewpoints of reactivity, boiling point, stability of the sealing end and price. These may be used alone or in combination of two or more.

  Although the said diamine compound is not specifically limited, For example, linear aliphatic diamines, such as hexamethylene diamine and pentamethylene diamine; Branched aliphatic diamines, such as 2-methylpentane diamine and 2-ethyl hexamethylene diamine; Aromatic diamines such as p-phenylenediamine and m-phenylenediamine; cycloaliphatic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine are listed. These may be used alone or in combination of two or more.

  The monocarboxylic acid compound is not particularly limited, and examples thereof include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyl. Aliphatic monocarboxylic acids such as acids; Alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; Aromatics such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid A monocarboxylic acid etc. are mentioned. In this invention, these carboxylic acid compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  The dicarboxylic acid compound is not particularly limited. For example, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid. Aliphatic dicarboxylic acids such as 3,3-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'-dicar Units derived from aromatic dicarboxylic acids such as phosphate and 4,4'-biphenyl dicarboxylic acid (unit) and the like. These may be used alone or in combination of two or more.

 In the present invention, the (A) polyamide resin is based on ISO 307, and the viscosity number (VN) measured with sulfuric acid having a mass fraction of 96% is 80 to 150 ml / g. It is preferable from the viewpoint of fluidity during molding. More preferably, it is 80-140 ml / g, More preferably, it is 100-140 ml / g.

  The blending amount of the (A) polyamide resin used in the present invention is preferably 30 to 95% by mass with respect to 100% by mass of the polyamide resin composition from the viewpoint of impact resistance and fluidity. More preferably, it is 51-95 mass%, More preferably, it is 60-94 mass%, Most preferably, it is 70-94 mass%.

[(B) ethylene / α-olefin copolymer (component (B))]
The polyamide resin composition of the present invention contains (B) an ethylene / α-olefin copolymer. By including the ethylene / α-olefin copolymer, the polyamide resin composition has excellent impact resistance.
The ethylene / α-olefin copolymer is a copolymer containing at least ethylene and α-olefin as constituent components.

  The ethylene / α-olefin copolymer used in the present invention is not limited to the following, but includes ethylene and at least one α-olefin having 3 to 20 carbon atoms as constituent components, and the following requirements: Is preferably a copolymer defined by Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 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, 12-ethyl-1-tetradecene and these See fit, and the like. Among these α-olefins, a copolymer using an α-olefin having 6 to 12 carbon atoms is more preferable because mechanical strength is improved and a reforming effect is further improved.

 The ethylene / α-olefin copolymer used in the present invention has a weight average molecular weight (Mw) and a number average molecular weight (Mw) calculated by gel permeation chromatography (GPC) from the viewpoint of impact resistance of the polyamide resin composition. The ratio (Mw / Mn) to Mn) is preferably 3.0 or less, more preferably 2.9 or less, and even more preferably 2.8 or less.

 The ethylene / α-olefin copolymer preferably has an α-olefin content of 6 to 25 mol%, more preferably 8 to 22 mol%, and still more preferably 10 to 20 mol%. By using an ethylene / α-olefin copolymer having an α-olefin content in the above range, a polyamide resin composition excellent in flexibility and impact resistance can be obtained.

 Although the manufacturing method of an ethylene-alpha-olefin copolymer is not limited to the following, it can manufacture by superposing | polymerizing using a metallocene catalyst. The metallocene catalyst is composed of a cyclopentadienyl derivative of a group IV metal such as titanium or zirconium and a cocatalyst. Metallocene catalysts are highly active, and the molecular weight distribution of the resulting polymer is narrow compared to conventional catalysts typified by Ziegler catalysts, and the distribution of α-olefin, which is a comonomer component of the copolymer, is uniform. It has the feature that it is excellent in flexibility and impact resistance.

The density of the ethylene / α-olefin copolymer used in the present invention is preferably 0.84 to 0.90 g / cm ³ from the viewpoint of impact resistance of the obtained polyamide resin composition. More preferably, it is 0.85-0.89 g / cm < ³ >, More preferably, it is 0.86-0.88 g / cm < ³ >. The density can be measured according to JIS K7122.

  The MFR measured at 190 ° C. under a load of 2.16 kg in accordance with ASTM D1238 of the ethylene / α-olefin copolymer used in the present invention is 20 to 20 from the viewpoint of impact resistance and fluidity of the obtained polyamide resin composition. 50 g / 10 min. Preferably it is 30-50 g / 10min, More preferably, it is 30-45g / 10min.

 The blending amount of the ethylene / α-olefin copolymer used in the present invention is 2 to 45% by mass with respect to 100% by mass of the polyamide resin composition from the viewpoint of impact resistance and fluidity of the obtained polyamide resin composition. Is preferred. More preferably, it is 2-40 mass%, More preferably, it is 2-30 mass%, Most preferably, it is 4-25 mass%.

[(C) Ethylene / α-olefin copolymer graft-modified with unsaturated carboxylic acid or derivative thereof (component (C))]
The polyamide resin composition of the present invention comprises (C) an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof. By including an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof, the polyamide resin composition has excellent impact resistance.
The ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is obtained by graft-modifying an ethylene / α-olefin copolymer with an unsaturated carboxylic acid or a derivative thereof.

The unsaturated carboxylic acid or derivative thereof is not limited to acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, citraconic acid. Glutaconic acid and metal salts of these carboxylic acids, methyl hydrogen maleate, methyl itaconic acid methyl, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- (2,2,1) -5 -Heptene-2,3-dica Boric acid, endobicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, methacrylic acid Glycidyl, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconic acid, and 5-norbornene-2,3-dicarboxylic acid.
In these, unsaturated dicarboxylic acid and its acid anhydride are preferable, Maleic acid, 5-norbornene-2,3-dicarboxylic acid or these acid anhydrides are more preferable, Maleic anhydride is especially preferable.

 An ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is prepared in the presence of a polymerization initiator such as an ethylene / α-olefin copolymer, an unsaturated carboxylic acid or a derivative thereof, and an organic peroxide. Or kneading in a solution prepared by dissolving an ethylene / α-olefin copolymer and an unsaturated carboxylic acid or derivative thereof in an organic solvent in the presence of a polymerization initiator such as an organic peroxide. Is obtained. Examples of the organic peroxide include organic peroxides and organic peroxides, and organic peroxides are preferable, and in particular, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,4-bis (t-butylperoxy) Isopropyl) benzene is preferably used.

 The preferred mass ratio of each component when producing an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is usually unsatisfactory with respect to 100 parts by mass of the ethylene / α-olefin copolymer. The saturated carboxylic acid or derivative thereof is preferably 0.01 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and the organic peroxide is preferably 0.001 to 2 parts by mass, more preferably 0. 0.005 to 1 part by mass.

 When melt-kneading, the reaction temperature is preferably 100 to 280 ° C, more preferably 180 to 260 ° C. When kneading in a solution, the reaction temperature is preferably 60 to 200 ° C, more preferably 80 to 180 ° C. The solvent used is xylene, toluene, dichlorobenzene and the like.

The modification rate (the amount of functional groups in the copolymer) of the ethylene / α-olefin copolymer graft-modified with the unsaturated carboxylic acid or derivative thereof thus obtained is the impact resistance of the polyamide resin composition. From the viewpoint of fluidity, 0.01 to 10% by mass is preferable, more preferably 0.1 to 3% by mass, and still more preferably 0.4 to 1.5% by mass. The modification rate can be controlled by the preparation ratio when the copolymer before modification is reacted with the unsaturated carboxylic acid or its derivative, and measured by ¹³ C-NMR measurement or ¹ H-NMR measurement. Can do.

(C) The density of the ethylene / α-olefin copolymer graft-modified with unsaturated carboxylic acid or a derivative thereof is 0.84 to 0.90 g / cm ³ from the viewpoint of impact resistance of the obtained polyamide resin composition. Is preferred. More preferably, it is 0.85-0.89 g / cm < ³ >, More preferably, it is 0.86-0.88 g / cm < ³ >. The density can be measured according to JIS K7122.

  (C) MFR measured at 190 ° C. under a load of 2.16 kg according to ASTM D1238 of an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is impact resistance of the obtained polyamide resin composition From the viewpoint of the above, it is 0.1 to 10 g / 10 minutes. Preferably it is 0.3-10 g / 10min, More preferably, it is 0.3-5 g / 10min.

  (C) Since the MFR of the ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is within the above range, the molecular weight of the copolymer that forms a graft product by reacting with polyamide increases. , Tend to improve impact resistance. On the other hand, the ethylene / α-olefin copolymer does not react with the polyamide, but is compatible with the ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof. As a result, the particle size of the ethylene / α-olefin copolymer dispersed in the polyamide and the ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or derivative thereof has a wide distribution. Therefore, the impact resistance and fluidity tend to be improved in a highly balanced manner.

 (C) The blending amount of the ethylene / α-olefin copolymer graft-modified with unsaturated carboxylic acid or its derivative is 100 mass of polyamide resin composition from the viewpoint of impact resistance and fluidity of the obtained polyamide resin composition. 2-45 mass% is preferable with respect to%. More preferably, it is 2-40 mass%, More preferably, it is 2-30 mass%, Most preferably, it is 2-20 mass%.

 (B) with respect to a total of 100% by mass of the ethylene / α-olefin copolymer and (C) an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or derivative thereof, The blending amount of the ethylene / α-olefin copolymer graft-modified with the derivative is preferably 10 to 80% by mass from the viewpoint of impact resistance and fluidity of the obtained polyamide resin composition. More preferably, it is 20-80 mass%, More preferably, it is 20-60 mass%, Most preferably, it is 40-60 mass%.

Examples of additional components are listed below.
Inorganic fillers, antioxidants, UV absorbers, heat stabilizers, photodegradation inhibitors, lubricants, plasticizers, mold release agents, nucleating agents, flame retardants, colorants, etc. can be added, and other heat A plastic resin may be blended.

Examples of the inorganic filler include, but are not limited to, glass fiber, carbon fiber, flaky glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, wollastonite, montmorillonite, and swellable fluorine. And mica and apatite.
These may be used alone or in combination of two or more.

  Among the glass fibers and carbon fibers, from the viewpoint of imparting excellent mechanical properties to the polyamide resin composition, the polyamide resin composition has a number average fiber diameter of 3 to 30 μm and a weight average fiber length of 100 to 750 μm. More preferably, the aspect ratio of the weight average fiber length to the number average fiber diameter (value obtained by dividing the weight average fiber length by the number average fiber diameter) is 10 to 100.

Further, the glass fiber or the carbon fiber may have a circular cross section or a flat shape (such as an elliptical shape or a saddle shape). A flat shape is preferable from the viewpoint of low warpage.
When the fiber diameter of the glass fiber is flat, the average minor axis is preferably 3 to 15 μm, more preferably 4 to 10 μm, and still more preferably, from the viewpoint of excellent mechanical strength, appearance, and low warpage. 5-9 μm.

  The compounding quantity of the inorganic filler used by this invention is 0-70 mass% with respect to 100 mass% of polyamide resin compositions from a viewpoint of mechanical strength and an external appearance. More preferably, it is 5-70 mass%, More preferably, it is 10-50 mass%.

Examples of the heat stabilizer include, but are not limited to, phenolic heat stabilizers, phosphorus heat stabilizers, amine heat stabilizers, groups Ib, IIb, and IIIa of the periodic table. Group, group IIIb, group IVa and group IVb element metal salts, alkali metal halides and alkaline earth metal halides, and the like.
These may be used alone or in combination of two or more.

  Although it does not restrict | limit especially as a phenol type heat stabilizer, For example, a hindered phenol compound is mentioned.

Examples of the hindered phenol compound include, but are not limited to, for example, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide), Pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-) Hydrocinnamamide), triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t-butyl) -4-hydroxy-5-methylphenyl) propynyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,5- -T-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, and 1, 3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.
In particular, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide)] is preferable from the viewpoint of improving heat aging resistance.

  When using a phenol-based heat stabilizer, the blending amount of the phenol-based heat stabilizer in the polyamide resin composition is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the (A) polyamide resin. Preferably it is 0.1-1 mass part. When it is within the above range, the heat aging resistance can be further improved and the amount of generated gas can be further reduced.

  Examples of the phosphorus-based heat stabilizer include, but are not limited to, for example, pentaerythritol type phosphite compound, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl Diisodecyl phosphite, phenyl di (tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di -T-butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, 4,4'-butylidene-bis (3- Methyl-6-tert-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4′-isopropylidene diphenyldiphosphite, 4,4′-isopropylidenebis (2-tert-butyl) Phenyl) -di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butanediphosphite , Tetra (tridecyl) -4,4′-butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4′-isopropylidene diphenyldiphosphite, tris (mono , Dimixed nonylphenyl) phosphite, 4,4′-isopropylidenebi (2-t-butylphenyl) -di (nonylphenyl) phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris (3,5 -Di-t-butyl-4-hydroxyphenyl) phosphite, hydrogenated-4,4'-isopropylidene diphenyl polyphosphite, bis (octylphenyl) -bis (4,4'-butylidenebis (3-methyl-6) -T-butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) diphosphite, tris (4, 4′-isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylenebis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylene diphosphite and tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene diphos Fight is mentioned.

When using a phosphorus heat stabilizer, the compounding quantity of the phosphorus heat stabilizer in the polyamide resin composition of this invention is 0.01-1 mass part with respect to 100 mass parts of (A) polyamide resin, More preferably, it is 0.1-1 mass part.
When it is within the above range, the heat aging resistance can be further improved and the amount of generated gas can be further reduced.

  Examples of amine heat stabilizers include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4 -Acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethyl Piperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethyl Piperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine 4- (ethylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy) -2, 2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -oxalate, Bis (2,2,6,6-tetramethyl-4-piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -sebacate, bis (2,2,6,6- Tetramethyl-4-piperidyl) -adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) -terephthalate, 1,2-bis (2,2,6,6) Tetramethyl-4-piperidyloxy) -ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6-tetra Methyl-4-piperidyltolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris (2,2,6 , 6-tetramethyl-4-piperidyl) -benzene-1,3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,4-tri Carboxylate, 1- [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} butyl] -4- [3- (3,5-di-t-butyl-4 -Hydroxyphenyl) Pionyloxy] 2,2,6,6-tetramethylpiperidine, and 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′ , Β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol.

 When the amine heat stabilizer is used, the compounding amount of the amine heat stabilizer in the polyamide resin composition of the present invention is preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the (A) polyamide. More preferably, it is 0.1-1 mass part. When it is within the above range, the heat aging resistance can be further improved, and the amount of generated gas can be further reduced.

  The metal salt of the elements of Group Ib, Group IIb, Group IIIa, Group IIIb, Group IVa and Group IVb of the periodic table is not particularly limited, but is preferably a copper salt. .

Examples of copper salts include, but are not limited to, copper halides (copper iodide, cuprous bromide, cupric bromide, cuprous chloride, etc.), copper acetate, copper propionate, copper benzoate. , Copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate and copper stearate, and copper complex salts in which copper is coordinated to a chelating agent such as ethylenediamine and ethylenediaminetetraacetic acid.
These may be used alone or in combination of two or more.

  Among the copper salts listed above, one or more selected from the group consisting of copper iodide, cuprous bromide, cupric bromide, cuprous chloride and copper acetate are preferred, and copper iodide is more preferred. And / or copper acetate.

When using a copper salt, the compounding amount of the copper salt in the polyamide resin composition of the present invention is preferably 0.01 to 0.2 parts by mass, more preferably 100 parts by mass of the (A) polyamide resin. Is 0.02-0.15 parts by mass.
When it is within the above range, the heat aging resistance can be further improved.

  Further, from the viewpoint of improving the heat aging resistance, the copper element content is preferably 10 to 500 ppm, more preferably 30 to 500 ppm, and even more preferably 50, based on the total amount of the polyamide resin composition of the present invention. ~ 300 ppm.

Examples of alkali metal halides and alkaline earth metal halides include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide and sodium chloride, and mixtures thereof.
In particular, from the viewpoint of improving the heat aging resistance, potassium iodide and potassium bromide, and mixtures thereof are preferable, and potassium iodide is more preferable.

  When an alkali metal halide and / or an alkaline earth metal halide is used, the compounding amount of the alkali metal halide and / or alkaline earth metal halide in the polyamide resin composition of the present invention is polyamide. Preferably it is 0.05-5 mass parts with respect to 100 mass parts, More preferably, it is 0.2-2 mass parts. When it is within the above range, the heat aging resistance is further improved, and copper precipitation and metal corrosion can be suppressed.

 The lubricant is not particularly limited, and examples thereof include fatty acid metal salts, fatty acid esters, fatty acid amides, and polyethylene waxes. From the viewpoint of excellent appearance and molding processability, one or more selected from fatty acid metal salts, fatty acid esters, and fatty acid amides are preferable, and two or more types are more preferable, and the fatty acid metal salt and the fatty acid ester are used in combination. More preferably.

Fatty acid refers to an aliphatic monocarboxylic acid. In particular, fatty acids having 8 or more carbon atoms are preferred. More preferably, it is a C8-C40 fatty acid.
Examples of fatty acids include, but are not limited to, saturated or unsaturated, linear or branched aliphatic monocarboxylic acids.
Examples of fatty acids include, but are not limited to, stearic acid, palmitic acid, behenic acid, erucic acid, oleic acid, lauric acid, and montanic acid.

A fatty acid ester is an ester compound of a fatty acid and an alcohol.
Examples of the alcohol include, but are not limited to, 1,3-butanediol, trimethylolpropane, stearyl alcohol, behenyl alcohol, lauryl alcohol, and the like.

  Examples of fatty acid esters include, but are not limited to, stearyl stearate, behenyl behenate, montanic acid-1,3-butanediol ester, montanic acid-trimethylolpropane ester, trimethylolpropane trilaurate. And butyl stearate.

The fatty acid amide is an amidated product of the fatty acid.
Examples of the fatty acid amide include, but are not limited to, stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearyl amide, ethylene bisoleyl amide, N-stearyl stearyl amide, N-stearyl erucamide. Etc. In particular, stearic acid amide, erucic acid amide, ethylene bisstearyl amide, and N-stearyl erucamide are preferable, and ethylene bisstearyl amide and N-stearyl erucamide are more preferable.

The fatty acid metal salt is a metal salt of the fatty acid described above.
Examples of metal elements that form salts with fatty acids include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), Group 3 elements, zinc, and aluminum in the Periodic Table of Elements.
As the metal element, alkali metals such as sodium and potassium; alkaline earth metals such as calcium and magnesium; aluminum are preferable.

Examples of the fatty acid metal salt include, but are not limited to, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, aluminum montanate, zinc montanate, and montan. Examples thereof include magnesium acid, calcium behenate, sodium behenate, zinc behenate, calcium laurate, zinc laurate, and calcium palmitate.
These fatty acid metal salts may be used alone or in combination of two or more.

 Although there is no restriction | limiting in particular in the compounding quantity of these lubricants, from a viewpoint of the outstanding external appearance and moldability, 0.01-1 mass% is preferable with respect to 100 mass% of polyamide resin compositions, and 0.03-0.6 % By mass is more preferable, and 0.05 to 0.5% by mass is more preferable.

 Although it does not restrict | limit especially as a coloring agent, For example, carbon black, a titanium oxide, an azine dye etc. are mentioned. Although there is no restriction | limiting in particular in the compounding quantity of these coloring agents, 0.01-3 mass% is preferable with respect to 100 mass% of polyamide resin compositions from a viewpoint of the outstanding external appearance and moldability, 0.05-2 mass % Is more preferable, and 0.1 to 2% by mass is more preferable.

In the present invention, the polyamide resin composition can be produced by a method of kneading the polyamide resin in a melted state using a single-screw or multi-screw extruder.
The composition thus obtained can be molded as molded parts of various parts by various conventionally known methods such as injection molding.

  These various parts can be suitably used for, for example, automobiles, machine industries, electric / electronics, industrial materials, industrial materials, and daily / household goods.

 EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Raw materials used)
(1) Polyamide Polyamide 66 (hereinafter abbreviated as PA)
VN (sulfuric acid): 130 ml / g, amino end group: 40 mmol / kg,
Carboxyl end group: 80 mmol / kg

(2) Ethylene / α-olefin copolymer (2-1) Ethylene / 1-butene copolymer (hereinafter abbreviated as EBR-1)
Density: 0.86 g / cm ³ , MFR (190 ° C., 2.16 kg load): 0.5 g / 10 min (2-2) ethylene / 1-butene copolymer (hereinafter abbreviated as EBR-2)
Density: 0.87 g / cm ³ , MFR (190 ° C., 2.16 kg load): 35 g / 10 min, MFR (230 ° C., 2.16 kg load): 65 g / 10 min (2-3) ethylene 1-octene Copolymer (hereinafter abbreviated as EOR)
Density: 0.86 g / cm ³ , MFR (190 ° C., 2.16 kg load): 0.5 g / 10 min

(3) Modified ethylene / α-olefin copolymer (3-1) Maleic anhydride modified ethylene / 1-butene copolymer (hereinafter abbreviated as modified EBR-1)
Density: 0.87 g / cm ³ , MFR (190 ° C., 2.16 kg load): 0.6 g / 10 min, modification rate: 1% by mass
(3-2) Maleic anhydride-modified ethylene / 1-butene copolymer (hereinafter abbreviated as modified EBR-2)
Density: 0.87 g / cm ³ , MFR (190 ° C., 2.16 kg load): 1.5 g / 10 min, modification rate: 0.8 mass%
(3-3) Maleic anhydride-modified ethylene / 1-butene copolymer (hereinafter abbreviated as modified EBR-3)
Density: 0.87 g / cm ³ , MFR (190 ° C., 2.16 kg load): 40 g / 10 min, MFR (230 ° C., 2.16 kg load): 70 g / 10 min Denaturation rate: 0.5 mass%
(3-4) Maleic anhydride-modified ethylene / 1-octene copolymer (hereinafter abbreviated as modified EOR)
Density: 0.87 g / cm ³ , MFR (190 ° C., 2.16 kg load): 1.6 g / 10 min, modification rate: 0.8% by mass

(4) Heat stabilizer Polyamide 6 (VN (sulfuric acid): 150 ml / g); 80% by mass, CuI; 4% by mass, KI; Master batch composed of 16% by mass (hereinafter abbreviated as HS)
(5) Colorant Polyamide 6 (VN (sulfuric acid): 150 ml / g); 80% by mass, CB (Mitsubishi Carbon (registered trademark) 52B); 15% by mass, ethylenebisstearic acid amide; 5% by mass Master batch (hereinafter abbreviated as CMB)

(Evaluation method)
The evaluation method is described below.
<Charpy impact strength>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide resin composition pellets obtained in the examples and comparative examples were injected + holding time 25 seconds, cooling time 15 seconds, mold temperature. A molded piece of ISO 3167, a multi-purpose test piece A type was molded at 80 ° C. and a molten resin temperature of 280 ° C. The obtained molded piece was cut and used, and a Charpy impact strength with a notch was measured at 23 ° C. and −30 ° C. according to ISO 179 / 1eA using a test piece of 80 mm × 10 mm × 4 mm, and −30 The impact strength retention rate at 23 ° C. at 23 ° C. was evaluated.

<Fluidity>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide resin composition pellets obtained in the examples and comparative examples were injected and held for 10 seconds, cooled for 15 seconds, and mold temperature. Was set at 80 ° C. and a molten resin temperature of 280 ° C., and a spiral flow mold having a width of 10 mm and a thickness of 2 mm was used, and the spiral flow length was measured under conditions of an injection pressure of 50 MPa and an injection speed of 150 mm / sec.

<Toughness during water absorption>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide resin composition pellets obtained in the examples and comparative examples were injected + holding time 25 seconds, cooling time 15 seconds, mold temperature. A molded piece of ISO 3167, a multi-purpose test piece A type was molded at 80 ° C. and a molten resin temperature of 280 ° C. Using the obtained molded piece, in accordance with ISO 527, a tensile test was performed at a tensile rate of 50 mm / min, and the tensile elongation at break (during drying) was measured. Also, after adjusting the multipurpose specimen A type to the equilibrium moisture content under the condition of humidity of 50 RH%, a tensile test was conducted at a tensile speed of 50 mm / min in accordance with ISO 527, and the tensile elongation at break (during water absorption) was determined. It was measured. The improvement in breaking elongation due to water absorption was evaluated.

[Examples 1-6, Comparative Examples 1-5]
L / D (extruder cylinder length / extruder cylinder diameter) = 48 (number of barrels: 12) twin screw extruder [ZSK-26MC: manufactured by Coperion (Germany)], supplied upstream From the mouth to the die is set to 280 ° C., the rotation speed of the screw is 300 rpm, the discharge rate is 25 kg / h, and the polyamide, ethylene / α-olefin copolymer, anhydrous A maleic acid-modified ethylene / α-olefin copolymer, a heat stabilizer and a colorant were supplied, and the mixture was melt-kneaded under reduced pressure from a vacuum devolatilization port to prepare a resin composition pellet. The obtained resin composition was molded at a resin temperature of 280 ° C. and a mold temperature of 80 ° C., and Charpy impact strength and fluidity were evaluated. The physical property values are shown together with the composition in Table 1. In Table 1, N.I. B. Indicates that the sample did not break and could not be quantified.

  As shown in Table 1, the polyamide resin composition of the present invention has low-temperature impact resistance as is apparent from Charpy impact strength, impact strength retention at 23 ° C. at −30 ° C., and improvement in tensile rupture elongation due to water absorption. Excellent fluidity. Therefore, if the polyamide resin composition of the present invention is used, impact resistance at 0 ° C. or less can be improved.

  Since the polyamide resin composition of the present invention is excellent in low temperature impact resistance and fluidity, it is suitably used as a molded article that requires good fluidity and requires low temperature impact resistance, such as automobile parts and small electric and electronic parts. be able to.

Claims (8)

(A) a polyamide resin;
(B) an ethylene / α-olefin copolymer having an MFR measured at 190 ° C. and a load of 2.16 kg according to ASTM D1238 of 20 to 50 g / 10 min;
(C) an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or derivative thereof having an MFR of 0.1 to 10 g / 10 min measured at 190 ° C. under a load of 2.16 kg according to ASTM D1238;
A polyamide resin composition comprising: The polyamide resin composition according to claim 1, wherein the density of the component (B) and / or the component (C) is 0.85 to 0.89 g / cm ³ .   The ethylene / α-olefin copolymer of the component (B) and / or the component (C) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Polyamide resin composition.   The polyamide resin composition according to any one of claims 1 to 3, wherein the unsaturated carboxylic acid or the derivative thereof as component (C) is maleic anhydride and the modification rate is 0.1 to 3% by mass. .   The polyamide resin composition according to any one of claims 1 to 4, wherein the component (A) has a viscosity number of 80 to 150 ml / g measured with sulfuric acid having a mass fraction of 96% in accordance with ISO 307. object.   The said (A) component is 51-95 mass% with respect to 100 mass% of polyamide resin compositions, the said (B) component is 2-45 mass%, and the said (C) component is 2-45 mass%. The polyamide resin composition according to any one of 1 to 5.   The polyamide resin composition according to any one of claims 1 to 6, wherein the component (C) is 20 to 60% by mass with respect to a total of 100% by mass of the component (B) and the component (C).   A method for improving impact resistance at 0 ° C. or lower using the polyamide resin composition according to claim 1.