JP6895322B2 - Polyamide resin composition - Google Patents

Description

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

Polyamide resins have excellent mechanical properties (mechanical strength, rigidity, impact resistance, etc.), 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 the polyamide resin is not sufficient in terms of impact resistance, particularly impact resistance at low temperatures, various studies have been conducted 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). Further, a method of blending a graft-modified ethylene / 1-butene copolymer with a polyamide resin has also been proposed (for example, Patent Document 3).

Special Publication No. 55-44108 Japanese Unexamined Patent Publication No. 55-9662 Japanese Unexamined Patent Publication No. 7-97503

In recent years, with the thinning of automobile parts and the miniaturization and precision of electrical and electronic parts, good fluidity is required.
However, the conventional technique 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 having excellent low temperature impact resistance and fluidity, which is suitable for automobile parts, small precision parts, and the like.

As a result of diligent studies to solve the above problems, the present inventors have graft-modified the ethylene / α-olefin copolymer contained in the polyamide resin composition with α, β-unsaturated carboxylic acid or a derivative thereof. We have found that the ethylene / α-olefin copolymer obtained is effective for obtaining a polyamide resin composition having excellent these properties when the MFR measured by a predetermined method is within a predetermined range, and the present invention has been made. Reached.

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

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

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

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

According to the present invention, it is possible to provide a polyamide resin composition having excellent low temperature impact resistance and fluidity.

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 ((A) component)]
"Polyamide" means a polymeric compound having a -CO-NH- (amide) bond in the main chain. The polyamide used in the present invention is not particularly limited, but for example, (a) a polyamide obtained by ring-opening polymerization of lactam, (b) a polyamide obtained by self-condensation of ω-aminocarboxylic acid, (c) diamine and Polyamides obtained by condensing dicarboxylic acids and copolymers thereof can be mentioned. The 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.

The lactam used as a raw material for the polyamide (a) is not particularly limited, and examples thereof include pyrrolidone, caprolactam, undecalactam, and dodecalactam.

The ω-aminocarboxylic acid used as a raw material for the polyamide resin (b) is not particularly limited, and examples thereof include ω-amino fatty acid, which is a ring-opening compound of lactam with water. The above-mentioned (a) polyamide and (b) polyamide may be condensed by using two or more kinds of lactam or ω-aminocarboxylic acid in combination.

Subsequently, the diamine (monomer) used as a raw material for the polyamide (c) is not particularly limited, but is, for example, a linear aliphatic diamine such as hexamethylenediamine or pentamethylenediamine; 2-methylpentanediamine. Bifurcated aliphatic diamines such as 2-ethylhexamethylenediamine and aromatic diamines such as p-phenylenediamine and m-phenylenediamine; alicyclic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine. Be done.

On the other hand, the dicarboxylic acid (monomer) used as a raw material for the polyamide (c) is not particularly limited, and is, for example, an aliphatic dicarboxylic acid such as adipic acid, pimelic acid or sebacic acid; phthalic acid or isophthalic acid. Aromatic dicarboxylic acid; alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid and the like can be mentioned.
The above-mentioned (c) polyamide may be condensed by one kind alone or by using two or more kinds of diamines and dicarboxylic acids in combination.

The polyamide is not particularly limited, but for example, polyamide 4 (poly α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecaneamide), polyamide 12 (polydodecaneamide), 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 (Polyhexamethylene terephthalamide), Examples thereof include polyamide 9T (polynonan methylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), and a copolymerized polyamide containing these as constituents.

The terminal group of the polyamide used in the present invention is not particularly limited, but generally includes an amino group or a carboxyl group. The ratio of the amino-terminal group amount to the total amount of the amino-terminal group amount and the carboxyl-terminal group amount in the polyamide used in the present invention [amino-terminal group amount / (amino-terminal group amount + carboxyl-terminal group amount)] is 0.2 or more and 1 It is preferably less than .5, more preferably 0.2 or more and 1.0 or less, and even more preferably 0.2 or more and 0.6 or less. When the ratio of the amount of terminal groups is within the above range, the color tone, mechanical strength, and vibration-resistant fatigue characteristics of the molded product obtained from the polyamide resin composition tend to be more excellent.

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

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

Further, as a method for adjusting the concentration of the terminal group of the polyamide used in the present invention, a known method can be used. The adjusting method is not particularly limited, and examples thereof include a method using a terminal adjusting agent. As a specific example, one or more terminal modifiers selected from the group consisting of monoamine compounds, diamine compounds, monocarboxylic acid compounds, and dicarboxylic acid compounds are added so as to have a predetermined terminal concentration during the polymerization of polyamide. Can be mentioned. The timing of adding the terminal adjusting agent to the solvent is not particularly limited as long as it fulfills its original function as the terminal adjusting agent, and for example, the above-mentioned polyamide raw material may be added to the solvent.

The monoamine compound is not particularly limited, and is, for example, an aliphatic monoamine such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine. Alicyclic monoamines such as cyclohexylamines and dicyclohexylamines; aromatic monoamines such as aniline, toluidine, diphenylamines and naphthylamines, 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 sealing terminal and price. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The diamine compound is not particularly limited, but is, for example, a linear aliphatic diamine such as hexamethylenediamine or pentamethylenediamine; or a branched aliphatic diamine such as 2-methylpentanediamine or 2-ethylhexamethylenediamine; Aromatic diamines such as p-phenylenediamine and m-phenylenediamine; alicyclic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine can be mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The monocarboxylic acid compound is not particularly limited, and is, for example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, lauric acid, tridecyl acid, myristyl acid, palmitic acid, stearic acid, pivalic acid and isobutyl. Alicyclic 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 Examples include monocarboxylic acid. In the present invention, these carboxylic acid compounds may be used alone or in combination of two or more.

The dicarboxylic acid compound is not particularly limited, and is, for example, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladiponic acid, trimethyladiponic acid, pimeric acid, 2,2-dimethylglutaric acid. , An aliphatic dicarboxylic acid such as 3,3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid; an alicyclic dicarboxylic acid 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, diphenylic acid, diphenylmethane- Examples thereof include units derived from aromatic dicarboxylic acids such as 4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid. These may be used individually by 1 type, and may be used in combination of 2 or more type.

In the present invention, the polyamide resin (A) conforms to ISO 307, and the viscosity number (VN) measured with sulfuric acid having a mass fraction of 96% is 80 to 150 ml / g, which is impact resistance and injection. It is preferable from the viewpoint of fluidity during molding. It is more preferably 80 to 140 ml / g, and even more preferably 100 to 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. It is more preferably 51 to 95% by mass, further preferably 60 to 94% by mass, and particularly preferably 70 to 94% by mass.

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

The ethylene / α-olefin copolymer used in the present invention is not limited to the following, but contains ethylene and at least one α-olefin having 3 to 20 carbon atoms as a constituent component, and the following requirements are required. It is preferably a copolymer defined by. Specific examples of the above-mentioned α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-hexene, 1-octene, 1-nonene, 1-decene, and 1-undecene. , 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-hexene, 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 Examples thereof include -1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene and combinations thereof. Among these α-olefins, a copolymer using an α-olefin having 6 to 12 carbon atoms is more preferable because the mechanical strength is improved and the modification 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, still 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 further 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 having excellent flexibility and impact resistance can be obtained.

The method for producing an ethylene / α-olefin copolymer is not limited to the following, but it can be produced by polymerizing using a metallocene-based catalyst. The metallocene-based catalyst is composed of a cyclopentadienyl derivative of a Group IV metal such as titanium and zirconium and a co-catalyst. The metallocene catalyst has high activity, the molecular weight distribution of the obtained polymer is narrower than that of the conventional catalyst represented by the Ziegler catalyst, and the distribution of α-olefin, which is a comonomer component of the copolymer, is uniform. It has the features of excellent 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.} It is more preferably 0.85 to 0.89 g / cm ³ , and even more preferably 0.86 to 0.88 g / cm ³ . Density can be measured according to JIS K7122.

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

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 preferable. It is more preferably 2 to 40% by mass, further preferably 2 to 30% by mass, and particularly preferably 4 to 25% by mass.

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

The unsaturated carboxylic acid or its derivative is not limited to, but is limited to acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, and citraconic acid. , Glutaconic acid and metal salts of these carboxylic acids, methyl hydrogen maleate, methyl hydrogen itaconic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, meta 2-Ethylhexyl acrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconic acid, maleic anhydride, itaconic acid anhydride, citraconic anhydride, endobicyclo- (2,2,1) -5 -Heptene-2,3-dicarboxylic acid, endobicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic acid anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide , Glycidyl acrylate, glycidyl methacrylate, glycidyl etacrilate, glycidyl itaconic acid, glycidyl citraconic acid, and 5-norbornene-2,3-dicarboxylic acid.
Of these, unsaturated dicarboxylic acids and their acid anhydrides are preferred, maleic acid, 5-norbornene-2,3-dicarboxylic acids or their acid anhydrides are more preferred, and maleic anhydride is particularly preferred.

The ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is obtained in the presence of a polymerization initiator such as an ethylene / α-olefin copolymer and an unsaturated carboxylic acid or a derivative thereof and an organic peroxide. In the presence of a polymerization initiator such as an organic peroxide in a solution in which an ethylene / α-olefin copolymer and an unsaturated carboxylic acid or a derivative thereof are dissolved in an organic solvent. Obtained by Examples of the organic peroxide include organic peroxides and organic peroxides, and organic peroxides are preferable, and dicumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-di (t-) are particularly preferable. Butylperoxy) hexin-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 preferable mass ratio of each component in producing an ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is usually unfavorable with respect to 100 parts by mass of the ethylene / α-olefin copolymer. Saturated carboxylic acid or a derivative thereof is preferably 0.01 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and organic peroxide is preferably 0.001 to 2 parts by mass, more preferably 0. It is an amount of .005 to 1 part by mass.

In the case of melt-kneading, the reaction temperature is preferably 100 to 280 ° C., more preferably 180 to 260 ° C., and in the case of kneading in a solution, the reaction temperature is preferably 60 to 200 ° C., more preferably 80 to 180 ° C. The temperature is ℃, and examples of the solvent used include xylene, toluene, and dichlorobenzene.

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

(C) The density of the ethylene / α-olefin copolymer graft-modified with an 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 preferable. It is more preferably 0.85 to 0.89 g / cm ³ , and even more preferably 0.86 to 0.88 g / cm ³ . Density can be measured according to JIS K7122.

(C) The MFR measured at 190 ° C. and 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 the impact resistance of the obtained polyamide resin composition. From the viewpoint of, it is 0.1 to 10 g / 10 minutes. It is preferably 0.3 to 10 g / 10 minutes, more preferably 0.3 to 5 g / 10 minutes.

(C) When 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 reacts with the polyamide to form a graft increases. , There is a tendency 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 size of the particles formed by the ethylene / α-olefin copolymer dispersed in the polyamide and the ethylene / α-olefin copolymer graft-modified with the unsaturated carboxylic acid or its derivative has a wide distribution. Therefore, there is a tendency that impact resistance and fluidity can be improved in a highly balanced manner.

(C) The blending amount of the ethylene / α-olefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof is 100 mass by mass of the polyamide resin composition from the viewpoint of impact resistance and fluidity of the obtained polyamide resin composition. 2 to 45% by mass is preferable with respect to%. It is more preferably 2 to 40% by mass, further preferably 2 to 30% by mass, and particularly preferably 2 to 20% by mass.

(C) Unsaturated carboxylic acid or (C) unsaturated carboxylic acid or (C) unsaturated carboxylic acid or (C) unsaturated carboxylic acid or (C) unsaturated carboxylic acid or (C) unsaturated carboxylic acid or 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. It is more preferably 20 to 80% by mass, further preferably 20 to 60% by mass, and particularly preferably 40 to 60% by mass.

Examples of additional ingredients are given below.
Inorganic fillers, antioxidants, UV absorbers, heat stabilizers, light deterioration inhibitors, lubricants, plasticizers, mold release agents, nuclear agents, flame retardants, colorants, etc. can be added, and other heat can be added. A plastic resin may be blended.

The inorganic filler is not limited to the following, and includes, for example, glass fiber, carbon fiber, flake-like glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, wollastonite, montmorillonite, and swellable fluorine. Examples include 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 number average fiber diameter is 3 to 30 μm and the weight average fiber length is 100 to 750 μm in the polyamide resin composition. And 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 more preferably 10 to 100.

Further, the glass fiber and the carbon fiber may have a circular cross section or a flat shape (oval shape, cocoon shape, etc.). A flat shape is preferable from the viewpoint of low warpage.
When the glass fiber is flat, the average minor axis is preferably 3 to 15 μm, more preferably 4 to 10 μm, and further preferably 4 to 10 μm from the viewpoint of excellent mechanical strength, appearance, and low warpage. It is 5-9 μm.

The blending amount of the inorganic filler used in the present invention is 0 to 70% by mass with respect to 100% by mass of the polyamide resin composition from the viewpoint of mechanical strength and appearance. It is more preferably 5 to 70% by mass, still more preferably 10 to 50% by mass.

The heat stabilizer is not limited to the following, but is, for example, a phenol-based heat stabilizer, a phosphorus-based heat stabilizer, an amine-based heat stabilizer, Group Ib, Group IIb, and Group IIIa of the periodic table. Examples thereof include metal salts of Group IIIb, Group IVa and Group IVb elements, and halides of alkali metals and halides of alkaline earth metals.
These may be used alone or in combination of two or more.

The phenolic heat stabilizer is not particularly limited, and examples thereof include hindered phenol compounds.

The hindered phenol compound is not limited to the following, but for example, N, N'-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide), Pentaerythrityl-tetrax [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) propionate] -4-Hydroxy-5-methylphenyl) propiniloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,5-di-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 (1,3,5-tris) 4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid can be mentioned.
In particular, from the viewpoint of improving heat resistance aging, N, N'-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide)] is preferable.

When a phenol-based heat stabilizer is used, the blending amount of the phenol-based heat stabilizer in the polyamide resin composition is preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the (A) polyamide resin, and more. It is preferably 0.1 to 1 part by mass. Within the above range, the heat resistant aging property can be further improved and the amount of generated gas can be further reduced.

The phosphorus-based heat stabilizer is not limited to the following, but is, for example, pentaerythritol type phosphite compound, trioctylphosphite, trilaurylphosphite, tridecylphosphite, octyldiphenylphosphite, trisisodecylphosphite, phenyl. Diisodecylphosphite, phenyldi (tridecyl) phosphite, diphenylisooctylphosphite, diphenylisodecylphosphite, diphenyl (tridecyl) phosphite, triphenylphosphite, 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-t-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4'-isopropyridene diphenyldiphosphite, 4,4'-isopropyridenebis (2-t-butylphenyl) -Di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-t-butyl-4-hydroxyphenyl) butanediphosphite, tetra (Tridecyl) -4,4'-butylidenebis (3-methyl-6-t-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4'-isopropyridene diphenyldiphosphite, tris (mono, di) Mixed nonylphenyl) phosphite, 4,4'-isopropyridenebis (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'-isopropyridene diphenylpolyphosphite, bis (octylphenyl) -Bis (4,4'-butylidenebis (3-methyl-6-t-butylphenyl))-1,6-hexanoldiphosphite, hexatridecyl-1,1,3-tris (2-methyl-4-tris) Hydroxy-5-t-butylphenyl) diphosphite, tris (4,4'-isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phospha 2,2-Methylenebis (4,6-di-t-butylphenyl) octylphosphite, 2,2-Methylenebis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexylphosphite, Tetraquis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylenediphosphite, and tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenedi Hosfite can be mentioned.

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

The amine-based heat stabilizer is not limited to the following, but is, for example, 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- Piperidine) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -sevacate, 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-tetramethyl-4-piperidyltrilen-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-tricarboxy Rate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,4-tricarboxylate, 1- [2- {3- (3,5-di-t-butyl) -4-Hydroxyphenyl) propionyloxy} butyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) p. Lopionyloxy] 2,2,6,6-tetramethylpiperidin, and 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β' , Β'-Tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] Condensate with diethanol.

When an amine-based heat stabilizer is used, the blending amount of the amine-based 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 (A) polyamide. , More preferably 0.1 to 1 part by mass. Within the above range, the heat-resistant aging property can be further improved, and the amount of generated gas can be further reduced.

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

The copper salt is not limited to the following, but is, for example, copper halide (copper iodide, cuprous bromide, cupric bromide, cuprous chloride, etc.), copper acetate, copper propionate, copper benzoate, etc. , Copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate and copper stearate, and copper complex salts in which copper is coordinated with a chelating agent such as ethylenediamine and ethylenediaminetetraacetic acid.
These may be used individually by 1 type, and may be used in combination of 2 or more type.

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

When a copper salt is used, the blending amount of the copper salt in the polyamide resin composition of the present invention is preferably 0.01 to 0.2 parts by mass with respect to 100 parts by mass of the (A) polyamide resin, which is more preferable. Is 0.02 to 0.15 parts by mass.
Within the above range, the heat resistant aging property can be further improved.

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

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 heat-resistant aging property, potassium iodide and potassium bromide, and a mixture thereof are preferable, and potassium iodide is more preferable.

When an alkali metal halide and / or an alkaline earth metal halide is used, the blending amount of the alkali metal halide and / or the alkaline earth metal halide in the polyamide resin composition of the present invention is polyamide. It is preferably 0.05 to 5 parts by mass, and more preferably 0.2 to 2 parts by mass with respect to 100 parts by mass. Within the above range, the heat-resistant aging property can be 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 moldability, one or more selected from fatty acid metal salts, fatty acid esters, and fatty acid amides are preferable, two or more are more preferable, and fatty acid metal salts and fatty acid esters are used in combination. Is even more preferable.

The fatty acid indicates an aliphatic monocarboxylic acid. In particular, fatty acids having 8 or more carbon atoms are preferable. More preferably, it is a fatty acid having 8 to 40 carbon atoms.
Fatty acids include, but are not limited to, saturated or unsaturated, linear or branched, aliphatic monocarboxylic acids.
Examples of the fatty acid 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.

The fatty acid ester is not limited to the following, and includes, for example, stearyl stearate, behenic behenate, montanic acid-1,3-butanediol ester, montanic acid-trimethylol propane ester, and trimethylol propane trilaurate. , Butyl stearate and the like.

The fatty acid amide is an amidate of the fatty acid.
The fatty acid amide is not limited to the following, but is, for example, stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearyl amide, ethylene bisoleyl amide, N-stearyl stearyl amide, N-stearyl erucamide. And so on. In particular, stearic acid amide, erucic acid amide, ethylene bisstearyl amide, and N-stearyl erkaamide are preferable, and ethylene bisstearyl amide and N-stearyl erkaamide are more preferable.

The fatty acid metal salt is the above-mentioned fatty acid metal salt.
Examples of the metal element forming a salt with the fatty acid include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), Group 3 elements, zinc, aluminum and the like in the Periodic Table of the Elements.
As the metal element, an alkali metal such as sodium and potassium; an alkaline earth metal such as calcium and magnesium; aluminum; is preferable.

The fatty acid metal salt is not limited to the following, and includes, for example, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, aluminum montanate, zinc montanate, and montanic acid. Examples thereof include magnesium acid, calcium behate, sodium behenate, zinc behenate, calcium laurate, zinc laurate, calcium palmitate and the like.
These fatty acid metal salts may be used alone or in combination of two or more.

The blending amount of these lubricants is not particularly limited, but from the viewpoint of excellent appearance and molding processability, 0.01 to 1% by mass is preferable with respect to 100% by mass of the polyamide resin composition, and 0.03 to 0.6. The mass% is more preferable, and 0.05 to 0.5% by mass is further preferable.

The colorant is not particularly limited, and examples thereof include carbon black, titanium oxide, and azine dyes. The blending amount of these colorants is not particularly limited, but from the viewpoint of excellent appearance and molding processability, 0.01 to 3% by mass is preferable with respect to 100% by mass of the polyamide resin composition, and 0.05 to 2% by mass is preferable. % Is more preferable, and 0.1 to 2% by mass is further preferable.

In the present invention, as a method for producing the polyamide resin composition, a method of kneading the polyamide resin in a molten state by a single-screw or multi-screw extruder can be used.
The composition thus obtained can be molded as a molded product of various parts by various conventionally known methods, for example, injection molding.

These various parts can be suitably used, for example, for automobiles, machine industry, electrical / electronic, industrial materials, industrial materials, and daily / household products.

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

(Ingredients used)
(1) Polyamide Polyamide 66 (hereinafter abbreviated as PA)
VN (sulfuric acid): 130 ml / g, amino-terminal group: 40 mmol / kg,
Carboxyl-terminal 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 minutes (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 minutes, MFR (230 ° C, 2.16 kg load): 65 g / 10 minutes (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 minutes

(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 minutes, denaturation 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 minutes, Degeneration rate: 0.8% by 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 minutes, MFR (230 ° C, 2.16 kg load): 70 g / 10 minutes Degeneration rate: 0.5% by 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 minutes, Degeneration rate: 0.8% by mass

(4) Heat Stabilizer Polyamide 6 (VN (sulfuric acid): 150 ml / g); 80% by mass, CuI; 4% by mass, KI; 16% by mass Masterbatch (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, ethylene bisstearic acid amide; 5% by mass Master batch (hereinafter abbreviated as CMB)

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

<Liquidity>
Using an injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], injection + holding pressure time of 10 seconds, cooling time of 15 seconds, and mold temperature of the polyamide resin composition pellets obtained in Examples and Comparative Examples were used. The spiral flow length was measured under the conditions of an injection pressure of 50 MPa and an injection speed of 150 mm / sec using a spiral flow mold having a width of 10 mm and a thickness of 2 mm at 80 ° C. and a molten resin temperature of 280 ° C.

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

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

As shown in Table 1, the polyamide resin composition of the present invention has low temperature impact resistance as is clear from the Charpy impact strength, the impact strength retention rate at -30 ° C at 23 ° C, and the degree of improvement in tensile elongation at break due to water absorption. Excellent and improved fluidity. Therefore, by using the polyamide resin composition of the present invention, the impact resistance at 0 ° C. or lower 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 product that is required to have good fluidity and low-temperature impact resistance, such as automobile parts and small electric / electronic parts. be able to.

Claims (7)

(A) Polyamide resin and
(B) An ethylene / α-olefin copolymer having an MFR of 20 to 50 g / 10 min measured at 190 ° C. and a load of 2.16 kg according to ASTM D1238.
(C) An ethylene / α-olefin copolymer having an MFR graft-modified with an unsaturated carboxylic acid or a derivative thereof having an MFR of 0.1 to 10 g / 10 min measured at 190 ° C. and a 2.16 kg load according to ASTM D1238.
A polyamide resin composition comprising,
The polyamide (A) component is 51 to 95% by mass, the (B) component is 2 to 45% by mass, and the (C) component is 2 to 45% by mass with respect to 100% by mass of the polyamide resin composition. Resin composition. 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 invention according to claim 1 or 2, wherein 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 of the component (C) or a derivative thereof 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. Stuff. The polyamide resin composition according to any one of claims 1 to 5 , 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 by using the polyamide resin composition according to any one of claims 1 to 6.