JP2017014388A - Polyamide resin composition and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition excellent in weather resistance and providing a molded body excellent in appearance and low warpage property.SOLUTION: There is provided a polyamide resin composition containing (A) a polyamide resin, (B) an inorganic filler and (C) carbon black, where at least a part of (A) the polyamide resin is (a1) aromatic polyamide, average primary particle diameter of (C) the carbon black is 20 nm or more and specific surface area/DBP oil absorption amount which is a ratio of specific surface area and DBP oil absorption amount is 1.0 or less.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition and a molded body formed by molding the polyamide resin composition.

  Polyamide resins have excellent mechanical properties (mechanical strength, rigidity, impact resistance, etc.), toughness, heat resistance, and chemical resistance, so traditionally, clothing, industrial materials, automobiles, electricity, electronics, etc. It is used in various industrial fields such as industry.

  However, polyamide resins are susceptible to oxidative degradation due to heat, ultraviolet rays, and the like, and therefore have limited use under conditions exposed to the outdoors. Conventionally, a technique of adding carbon black is known as a technique for improving the weather resistance of a polyamide resin (see, for example, Patent Documents 1, 2, and 3).

JP 2006-519909 A JP 2000-53861 A JP 2001-131408 A

However, it is not yet sufficient in terms of use under conditions where it is exposed to the outdoors for a longer period of time, and a polyamide resin composition having excellent weather resistance at a higher level is demanded. Furthermore, in automobile exterior applications and the like, a better appearance and lower warpage than ever are required.
This invention is made | formed in view of the said situation, and it aims at providing the polyamide resin composition from which the molded object excellent in the external appearance and the low warpage property is obtained while being excellent in a weather resistance.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyamide resin composition containing an aromatic polyamide, an inorganic filler, and a predetermined carbon black can solve the above problems. The present invention has been completed.

That is, the polyamide resin composition of the present invention is
(A) a polyamide resin;
(B) an inorganic filler;
(C) carbon black;
A polyamide resin composition comprising:
(A) At least a part of the polyamide resin is (a1) an aromatic polyamide,
(C) Carbon black has an average primary particle diameter of 20 nm or more, and a specific surface area / DBP oil absorption which is a ratio of a specific surface area to a DBP oil absorption is 1.0 or less.

(A) It is preferable that the ratio of the structural unit which has an aromatic structure with respect to 100 mass% of all the structural units which comprise a polyamide resin is 5-100 mass%.
Here, the structural unit means a unit constituting one -CO-NH- (amide) bond. When the raw material of the polyamide resin is lactam or ω-aminocarboxylic acid, the structural unit is a single structural unit. In the case of diamine and dicarboxylic acid, one pair of diamine and dicarboxylic acid is one structural unit.

  The (A) polyamide resin contains (a2) aliphatic polyamide as an optional component, and the ratio of (a1) aromatic polyamide to 100% by mass of (A) polyamide resin is 10% by mass to 100% by mass, (a2) aliphatic The proportion of polyamide is preferably 0% by mass or more and 90% by mass or less.

  (A1) The aromatic polyamide may contain at least one selected from polyamide 4T, polyamide 4I, polyamide 6T, polyamide 6I, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10 and polyamide PXD12 as a constituent component. preferable.

  (A2) The aliphatic polyamide is composed of polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 410, polyamide 412, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, and at least one of these components It is preferable that it is at least 1 sort (s) chosen from the copolyamide included as.

(C) The average primary particle diameter of carbon black is preferably 35 nm or more.
(C) It is preferable that the specific surface area of carbon black is 100 m < ² > / g or less.
(C) DBP oil absorption amount of carbon black ^is preferably 100 cm 3/100 g or more.

The polyamide resin composition may further contain (D) a copper compound, and (D) the copper compound is a copper halide compound, copper thiocyanate, copper nitrate, copper acetate, naphthene copper, copper caprate, copper laurate, It is preferably at least one selected from copper stearate, acetylacetone copper, copper (I) oxide and copper (II) oxide.
The polyamide resin composition preferably further contains (E) a halide of an alkali metal and / or alkaline earth metal.

The polyamide resin composition preferably further contains (F) a crystallization retarder.
(F) The crystallization retarder is preferably an azine dye or a phthalocyanine dye.

  The polyamide resin composition may further contain (G) a lubricant, and (G) the lubricant may be at least one selected from higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts, and polyolefin waxes. preferable.

  The ratio of (B) inorganic filler to 100% by mass of the polyamide resin composition is preferably 30% by mass or more and 70% by mass or less.

The molded article of the present invention is formed by molding the polyamide resin composition of the present invention.
The molded body is more suitable for automobile exterior parts.

  The polyamide resin composition of the present invention includes (A) a polyamide resin, (B) an inorganic filler, and (C) carbon black, and (A) at least a part of the polyamide resin is (a1) an aromatic polyamide. (C) Since the average primary particle diameter of the carbon black is 20 nm or more and the ratio of the specific surface area to the DBP oil absorption [specific surface area / DBP oil absorption] is 1.0 or less, the weather resistance is excellent. In addition, a molded article excellent in appearance and low warpage can be obtained.

Hereinafter, the present invention will be described in detail.
[Polyamide resin composition]
The polyamide resin composition of the present invention includes (A) a polyamide resin, (B) an inorganic filler, and (C) carbon black, and (A) at least a part of the polyamide resin is (a1) an aromatic polyamide. The carbon black (C) has an average primary particle diameter of 20 nm or more and a specific surface area / DBP oil absorption [specific surface area / DBP oil absorption] of 1.0 or less.

Hereinafter, each component of the polyamide resin composition will be described in detail.
(A) Polyamide resin (A) Polyamide resin (hereinafter sometimes simply referred to as “polyamide resin” or “component (A)”) means a polymer compound having a —CO—NH— (amide) bond in the main chain. To do.
In the present invention, the (A) polyamide resin contains (a1) an aromatic polyamide at least partially in order to obtain a resin composition having low warpage and improved appearance.

(A1) Aromatic polyamide (a1) Aromatic polyamide (hereinafter sometimes simply referred to as component (a1)) means a polyamide containing an aromatic ring in the molecule, and is used as a raw material for the polyamide resin. It is sufficient that the monomer contains an aromatic ring-containing monomer. Specifically, it may contain an aromatic diamine, a diamine having an aromatic ring, an aromatic dicarboxylic acid, and / or a dicarboxylic acid having an aromatic ring. When the total amount of raw material monomers constituting the polyamide is 100 mol%, it is preferable to use 5 mol% or more of a monomer containing an aromatic ring in the molecule during polymerization from the viewpoint of improving the low warpage and appearance. In addition, when calculating all the raw material monomers here, the diamine and dicarboxylic acid are calculated as 2 mol when the diamine is 1 mol and the dicarboxylic acid is 1 mol, for example.

The monomer containing an aromatic ring in the molecule is not limited to the following, but examples thereof include diamines having an aromatic ring such as m-xylylenediamine and p-xylylenediamine, p-phenylenediamine and m-phenylene. Aromatic diamines such as diamines, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. These diamines having aromatic rings, aromatic diamines and / or aromatic dicarboxylic acids may be used alone or in combination of two or more.
When the aromatic polyamide is obtained by condensation of a diamine and a dicarboxylic acid, at least one of the diamine and the dicarboxylic acid may be a diamine having an aromatic ring, an aromatic diamine, or an aromatic dicarboxylic acid.

  Specific examples of the (a1) aromatic polyamide are not limited to the following, but include, for example, polyamide 4T (polytetramethylene terephthalamide), polyamide 4I (polytetramethylene isophthalamide), polyamide 6T (poly Hexamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), polyamide MXD6 (poly m-xylylene adipamide), polyamide MXD10 (poly m-xylylene sebacamide), polyamide MXD12 (poly m-xylylene) Dodecamide), polyamide PXD6 (poly p-xylylene adipamide), polyamide PXD10 (poly p-xylylene sebacamide), polyamide PXD12 (poly p-xylylene dodecamide), and co-components containing these as constituents Polymerized polyamide It is.

As a constituent component of the copolymer, it is not necessary to have an aromatic ring as a raw material, but a raw material of polyamide resin, lactam, ω-aminocarboxylic acid, aliphatic diamine, alicyclic diamine, aliphatic dicarboxylic acid, alicyclic A group dicarboxylic acid or the like may be copolymerized.
Examples of the lactam include, but are not limited to, pyrrolidone, caprolactam, undecaractam, and dodecaractam.
Examples of the ω-aminocarboxylic acid include, but are not limited to, ω-amino fatty acids which are ring-opening compounds of the above lactams with water. The lactam or ω-aminocarboxylic acid may be condensed with two or more monomers in combination.

  Examples of diamines include, but are not limited to, linear aliphatic diamines such as tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, and decane diamine; 2-methylpentane diamine and 2-ethyl hexa Branched aliphatic diamines such as methylenediamine; diamines having aromatic rings such as p-xylylenediamine and m-xylylenediamine; aromatic diamines such as p-phenylenediamine and m-phenylenediamine; cyclohexanediamine and cyclopentane Examples include alicyclic diamines such as diamine and cyclooctanediamine.

  Examples of dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids such as adipic acid, pimelic acid, sebacic acid and dodecanedioic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. An alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid.

  (A1) Specific examples of the copolymer contained in the aromatic polyamide are not limited to the following, but examples include polyamide 66 / 4I, polyamide 66 / 4I / 6, polyamide 6 / 4I, polyamide 66 / 4T, polyamide 66 / 4T / 6, polyamide 6 / 4T, polyamide 66 / 4I / 4T, polyamide 66 / 4I / 4T / 6, polyamide 6 / 4I / 4T, polyamide 610 / 4I, polyamide 610 / 4I / 6, polyamide 610 / 4T, polyamide 610 / 4T / 6, polyamide 610 / 4I / 4T, polyamide 610 / 4I / 4T / 6, polyamide 66 / 6I, polyamide 66 / 6I / 6, polyamide 6 / 6I, polyamide 66 / 6T, polyamide 66 / 6T / 6, polyamide 6 / 6T, polyamide 66 / 6I / 6T, polyamide 6 / 6I / 6T / 6, polyamide 6 / 6I / 6T, polyamide 610 / 6I, polyamide 610 / 6I / 6, polyamide 610 / 6T, polyamide 610 / 6T / 6, polyamide 610 / 6I / 6T, polyamide 610 / 6I / 6T / 6, polyamide 612 / 6I, polyamide 612 / 6I / 6, polyamide 612 / 6T, polyamide 612 / 6T / 6, polyamide 612 / 6I / 6T, polyamide 612 / 6I / 6T / 6, polyamide 6T / 6I, polyamide 6T / 6I / 6, polyamide 6I / 6T, polyamide 6I / 6T / 6, polyamide MXD6 / 6I, polyamide MXD6 / 6T, polyamide MXD6 / 6I / 6T, polyamide MXD6 / 610, polyamide MXD6 / 66, polyamide MXD6 / 610, Polyamide MXD6 / P D6, polyamide PXD6 / 6I, polyamide PXD6 / 6T, polyamide PXD6 / 6I / 6T, polyamide PXD6 / 66, polyamide PXD6 / 610, and the like polyamide PXD6 / 612.

  Among the (a1) aromatic polyamides listed above, from the viewpoint of improving the appearance, polyamide 4T, polyamide 4I, polyamide 6T, polyamide 6I, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10, and polyamide PXD12 are selected. Polyamide containing at least one selected from the above as a constituent component is preferable. More preferably, polyamide 6T, polyamide 6I, polyamide 6T / 6I, polyamide 6I / 6T, polyamide 6T / 6I / 6, polyamide 6I / 6T / 6, polyamide 66 / 6I, polyamide 66 / 6I / 6, polyamide 6 / 6I , Polyamide 66 / 6I / 6T, polyamide 66 / 6I / 6T / 6, polyamide 6 / 6I / 6T, polyamide 610 / 6I, polyamide 610 / 6I / 6, polyamide 610 / 6T, polyamide 610 / 6T / 6, polyamide 610 / 6I / 6T, polyamide 610 / 6I / 6T / 6, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10, polyamide PXD12, more preferably polyamide 6I / 6T, polyamide 6T / 6I / 6, Reamide 6I / 6T / 6, Polyamide 66 / 6I, Polyamide 66 / 6I / 6, Polyamide 6 / 6I, Polyamide 66 / 6I / 6T, Polyamide 66 / 6I / 6T / 6, Polyamide 6 / 6I / 6T, Polyamide 6T / 6I, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10, polyamide PXD12, particularly preferably polyamide 6T / 6I, polyamide 6I / 6T, polyamide 6T / 6I / 6, polyamide 6I / 6T / 6, PA66 / 6I, PA66 / 6I / 6, PA66 / 6I / 6T, PA66 / 6I / 6T / 6, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10, and polyamide PXD12. The aromatic polyamide described above may be used alone or in combination of two or more.

  (A) The ratio of the (a1) aromatic polyamide to 100% by mass of the polyamide resin is preferably 10% by mass or more and 100% by mass or less from the viewpoint of low warpage and appearance of the molded product, and more preferably 30% by mass. It is 100 mass% or less, More preferably, it is 50 mass% or more and 100 mass% or less.

(A2) Aliphatic Polyamide The (A) polyamide resin of the present invention may contain (a2) an aliphatic polyamide (hereinafter sometimes simply referred to as component (a2)). The (a2) aliphatic polyamide in the present invention means a polyamide that does not contain an aromatic ring in the molecule, and includes a polyamide obtained by polymerizing an aliphatic diamine and an aliphatic dicarboxylic acid, an aliphatic diamine and an alicyclic dicarboxylic acid. Polymerized polyamide, polyamide obtained by polymerizing alicyclic diamine and aliphatic dicarboxylic acid, polyamide obtained by polymerizing alicyclic diamine and alicyclic dicarboxylic acid, aliphatic lactam and / or aliphatic aminocarboxylic acid Polymerized polyamides and copolymers thereof. Lactam, ω-aminocarboxylic acid, aliphatic diamine, alicyclic diamine, aliphatic dicarboxylic acid, and alicyclic dicarboxylic acid, which are raw materials for the polyamide resin as described above, can be used without any problem.

  The aliphatic polyamide obtained by condensing diamine and dicarboxylic acid is not limited to the following, but polyamide 46 (polytetramethylene adipamide), polyamide 410 (polytetramethylene sebacamide), polyamide 412 (polytetramethylene dodecamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 1010 (polydecane sebamide) And polyamide 1012 (polydecane decanamide).

  The aliphatic polyamide obtained by ring-opening polymerization of lactam is not limited to the following, but is polyamide 4 (poly α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide) and the like.

Moreover, these copolymers can also be used without a problem. Examples of the copolymer include, but are not limited to, polyamide 46/6, polyamide 410/6, polyamide 412/6, polyamide 66/6, polyamide 610/6, polyamide 612/6, and polyamide 1010/6. , Polyamide 1012/6, polyamide 610/11, polyamide 612/11, polyamide 1010/11, polyamide 1012/11, polyamide 610/12, polyamide 612/12, polyamide 1010/12, polyamide 1012/12 and the like.
(A2) Aliphatic polyamide mentioned above may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the present invention, (a2) aliphatic polyamide is polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 410, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012 and at least one selected from these. Copolymer polyamide containing as a constituent is preferred.

  (A) The ratio of (a2) aliphatic polyamide to 100% by mass of the polyamide resin is preferably 0% by mass or more and 90% by mass or less from the viewpoint of low warpage and appearance of a molded product, and more preferably 0% by mass or more. It is 70 mass% or less, More preferably, it is 0 mass% or more and 50 mass% or less.

  In the present invention, (A) the polyamide resin is preferably 5 to 100% by mass of the structural unit having an aromatic structure with respect to 100% by mass of all the structural units constituting the (A) polyamide resin from the viewpoint of improving the appearance. More preferably, it is 10-75 mass%, More preferably, it is 10-60 mass%, More preferably, it is 10-50 mass%, Most preferably, it is 10-30 mass%. The structural unit mentioned here means a unit constituting one —CO—NH— (amide) bond, and when the raw material is lactam and / or ω-aminocarboxylic acid, it becomes a structural unit alone, When obtained by polycondensation of diamine and dicarboxylic acid, one pair of diamine and dicarboxylic acid constitutes one structural unit.

  For example, in the case of a polyamide 66 / 6I / 6 copolymer polyamide, there are structural units composed of hexamethylenediamine and adipic acid, structural units composed of hexamethylenediamine and isophthalic acid, and structural units composed of ε-caprolactam. The ratio of the structural unit consisting of hexamethylenediamine and isophthalic acid to the total of 100% by mass is a structural unit having an aromatic structure. Moreover, when it is difficult to specify a structural unit, for example, when comprised from 2 or more types of diamine and 2 or more types of dicarboxylic acid, the diamine which has an aromatic ring with respect to 100 mass% of all the diamine which comprises a polyamide resin, and The total of the ratio of the aromatic diamine and the ratio of the dicarboxylic acid having an aromatic ring and / or the aromatic dicarboxylic acid with respect to 100% by mass of the total dicarboxylic acid is the ratio of the structural unit having an aromatic structure.

Further, when (A) the polyamide resin is a mixture of (a1) aromatic polyamide and (a1) an aromatic polyamide and (a2) an aliphatic polyamide, 100 (A) all the structural units constituting the polyamide resin are 100. Mass%. For example, in the case of a mixture of polyamide 66 / 6I and polyamide 6, there are structural units composed of hexamethylenediamine and adipic acid, structural units composed of hexamethylenediamine and isophthalic acid, and structural units composed of ε-caprolactam. Is 100% by mass. And the ratio of the structural unit which consists of hexamethylenediamine and isophthalic acid with respect to 100 mass% of these total is a structural unit which has an aromatic.
(A) Although the calculation method of the aromatic-containing monomer ratio in a polyamide resin is not specifically limited, it can be determined by a nuclear magnetic resonance method (NMR) or the like.

(A) As a terminal group of a polyamide resin, an amino group or a carboxyl group is generally present.
The ratio of terminal groups in the polyamide resin is preferably 9/1 to 1/9, more preferably 6/4 to 1/9, more preferably 5/5 to 5 as amino group concentration / carboxyl group concentration. 1/9. When the ratio of the terminal groups is within the above range, the mechanical strength of the polyamide resin composition of the present invention can be further improved.

  The density | concentration of the amino-group terminal in a polyamide resin becomes like this. Preferably it is 10-100 micromol / g, More preferably, it is 15-80 micromol / g, More preferably, it is 30-80 micromol / g. When the amino group terminal concentration in the polyamide resin is within the above range, the mechanical strength of the polyamide resin composition of the present invention can be further improved.

The concentration of the carboxyl group terminal in the polyamide resin is preferably 20 μmol / g or more, more preferably 50 μmol / g or more, still more preferably 50 to 120 μmol / g, even more preferably 50 to 100 μmol / g. is there. When the concentration of the carboxyl group terminal in the polyamide resin is within the above range, the heat aging resistance of the polyamide resin composition of the present invention can be further improved.
Here, the density | concentration of the amino group terminal of a polyamide resin and a carboxyl group terminal is measured by < ¹ > H-NMR, and can be calculated | required by the integral value of the characteristic signal corresponding to each terminal group.

The concentration of the terminal group of the polyamide resin can be adjusted as appropriate, and a known method can be used as a method for adjusting the terminal group. Although not limited to the following, for example, a method using a terminal adjusting agent can be mentioned.
Specifically, it is adjusted by adding one or more selected from the group consisting of a monoamine compound, a diamine compound, a monocarboxylic acid compound, and a dicarboxylic acid compound so that a predetermined terminal concentration is obtained during polymerization of the polyamide resin. can do.
The timing of addition of these components to the polymerization solvent is not particularly limited as long as it functions as a terminal adjuster. For example, a method of adding the above-mentioned polyamide resin raw material to the polymerization solvent Is mentioned.

Examples of monoamine compounds include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Aliphatic monoamines; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine, and any mixtures thereof.
These monoamine compounds may be used alone or in combination of two or more.

  In particular, the monoamine compound is selected from the group consisting of butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline from the viewpoints of reactivity, boiling point, sealing end stability, and price. One or more of these are preferred.

Examples of the diamine compound include, but are not limited to, linear aliphatic diamines such as hexamethylene diamine and pentamethylene diamine; branched types such as 2-methylpentane diamine and 2-ethyl hexamethylene diamine. Aliphatic diamines; aromatic diamines such as p-phenylenediamine and m-phenylenediamine; and alicyclic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine.
These diamine compounds may be used alone or in combination of two or more.

Examples of the monocarboxylic acid compound include, but are not limited to, for example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, Aliphatic monocarboxylic acids such as pivalic acid and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid And aromatic monocarboxylic acids such as
These monocarboxylic acid compounds may be used alone or in combination of two or more.

Examples of the dicarboxylic acid compound include, but are not limited to, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2 -Aliphatic dicarboxylic acids such as dimethylglutaric acid, 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 Acid: isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphen Acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dica Units derived from an aromatic dicarboxylic acid such as carbon acid and 4,4'-biphenyl dicarboxylic acid.
These dicarboxylic acid compounds may be used alone or in combination of two or more.

  Examples of the method for producing the polyamide resin used in the present invention include a melt polymerization method, a solid phase polymerization method, a bulk polymerization method, a solution polymerization method, or a combination of these from salts of adipic acid, isophthalic acid and hexamethylenediamine. Etc., various polycondensation can be used. It can also be obtained from adipic acid chloride, isophthalic acid chloride and hexamethylenediamine by methods such as solution polymerization and interfacial polymerization. Among these, a melt polymerization or a method based on a combination of melt polymerization and solid phase polymerization is preferable economically.

  The polyamide resin used in the present invention preferably has a formic acid solution viscosity at 25 ° C. ((polyamide 5.5 g) / (90% formic acid 50 mL)) of 10 or more and 45 or less as measured in accordance with JIS-K6920-2 appendix JA. . More preferably, it is 15-35, More preferably, it is 25-35, More preferably, it is 25-33. When the formic acid solution has a viscosity of 10 or more, embrittlement of the resin composition can be suppressed, and a molded product having practically sufficient mechanical properties can be obtained. Further, the rolling from the nozzle tip of the cylinder hardly occurs during molding. be able to. When the formic acid solution has a viscosity of 45 or less, the melt viscosity of the resin does not become too high, the partial lift of the inorganic filler during molding can be suppressed, and the surface gloss can be maintained.

(B) Inorganic filler (B) Inorganic filler (hereinafter sometimes referred to as inorganic filler or (B) component) is not limited to the following, but examples thereof include glass fiber and carbon fiber. , Calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, flaky glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, zinc oxide, calcium monohydrogen phosphate, wollastonite, silica , Zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, Ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper , Silver, aluminum, d Examples include nickel, iron, calcium fluoride, mica, montmorillonite, swellable fluorine mica, and apatite.
These may be used alone or in combination of two or more.

  Among those exemplified above, from the viewpoint of increasing the mechanical strength and rigidity of the polyamide resin composition of the present invention, glass fiber, carbon fiber, flaky glass, talc, kaolin, mica, calcium carbonate, calcium monohydrogen phosphate, One or more selected from the group consisting of lastonite, silica, carbon nanotubes, graphite, calcium fluoride, montmorillonite, swellable fluoromica and apatite are preferred. More preferably, it is at least one selected from the group consisting of glass fiber, carbon fiber, wollastonite, talc, mica, kaolin and silicon nitride.

  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.

  In addition, among the wollastonites, from the viewpoint that excellent mechanical properties can be imparted 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 10 to 10. More preferably, it is 500 μm and the aspect ratio is 3 to 100.

  In addition, among talc, mica, kaolin, and silicon nitride, those having a number average particle size in the polyamide resin composition of 0.1 to 10 μm from the viewpoint of imparting excellent mechanical properties to the polyamide resin composition Is more preferable.

Here, the number average fiber diameter, the number average particle diameter, and the weight average fiber length in the inorganic filler are values measured by the following method.
The polyamide resin composition is put into an electric furnace, the contained organic matter is incinerated, and, for example, 100 or more inorganic fillers are arbitrarily selected from the residue, and observed with an SEM (Scanning Electron Microscope). Then, the number average fiber diameter and the number average particle diameter are measured by measuring the fiber diameter and the particle diameter of these inorganic fillers. In addition, the weight average fiber length is obtained by measuring the fiber length using an SEM photograph at a magnification of 1000 times.

The inorganic filler may be surface-treated with a silane coupling agent or the like. Examples of the silane coupling agent include, but are not limited to, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-β- (aminoethyl) -γ-aminopropylmethyldimethoxy. Aminosilanes such as silane; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes.
In particular, at least one selected from the above listed components is preferable, and aminosilanes are more preferable.

  In addition, for glass fibers and carbon fibers, as sizing agents, constituent units include carboxylic acid anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers excluding carboxylic acid anhydride-containing unsaturated vinyl monomers. Copolymers, epoxy compounds, polycarbodiimide compounds, polyurethane resins, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and their primary, secondary or tertiary amines Or a salt thereof. These may be used alone or in combination of two or more.

Glass fiber and carbon fiber are obtained by continuously reacting in a known glass fiber and carbon fiber production process. Specifically, glass fibers and carbon fibers are obtained by drying fiber strands produced by applying a sizing agent to glass fibers and carbon fibers using a known method such as a roller-type applicator.
The fiber strand may be used as it is as roving, or may be used as a chopped glass strand after further cutting. Moreover, drying of a strand may be performed after a cutting process, or a cutting process may be performed after drying of a strand.

  From the viewpoint of maintaining the bundling of the glass fiber and the carbon fiber, the addition amount of the bundling agent is preferably equivalent to 0.2% by mass or more as a solid content with respect to 100% by mass of the glass fiber or the carbon fiber. On the other hand, from the viewpoint of improving the thermal stability of the polyamide resin composition of the present invention, the content is preferably 3% by mass or less.

  The ratio of the inorganic filler to 100% by mass of the polyamide resin composition is preferably 1% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and still more preferably 50% by mass or more and 60% by mass. % Or less. By setting the content of the inorganic filler to 1% by mass or more with respect to 100% by mass of the polyamide resin composition, the mechanical strength of the polyamide resin composition of the present invention is improved, and the content is 70% by mass or less. By doing, the polyamide resin composition excellent in a moldability is obtained.

(C) Carbon black (C) Carbon black (hereinafter sometimes simply referred to as carbon black or (C) component) is classified into furnace black, channel black, thermal black, etc. depending on its production method. Depending on the difference, they are classified into acetylene black, ketjen black, oil black, gas black and the like, but can be used without particular limitation in the present invention.

  The average primary particle diameter of carbon black is 20 nm or more, preferably 30 nm or more, more preferably 35 nm or more, still more preferably 50 nm or more, and particularly preferably 60 nm or more and 100 nm or less. When the average primary particle diameter is within this range, it is preferable because the weather resistance can be further improved. The average primary particle size is obtained by obtaining an image in which carbon black particles are dispersed by the procedure described in the standard of ASTM D3849 (standard test method of carbon black-morphological characterization by electron microscopy). It is a value obtained by measuring the diameter of 1,000 particles and obtaining the average value of the measured values.

The specific surface area of carbon black is preferably 100 m ² / g or less, more preferably 85 m ² / g or less, still more preferably 70 m ² / g or less, particularly preferably 50 m ² / g or less, and most preferably 30 m ² / g or less. When the specific surface area is within this range, low warpage, surface appearance, and weather gloss retention can be further improved, which is preferable. The specific surface area of carbon black is a value measured from the amount of nitrogen adsorption according to JIS K6217.

DBP oil absorption of the carbon black (the amount of dibutyl phthalate which carbon black 100g absorbs) is preferably 100cm ³ / 100g or more, and more preferably not more than 100cm ³ / 100g or more 300 cm ³ / 100g, more preferably 100cm ^3/100 g or more 200cm and a ^3/100 g or less, still more preferably not more than 100 cm ^3/100 g or more 150 cm ^3/100 g. When the DBP oil absorption is within this range, the low warpage, weather gloss retention and weather resistance can be further improved. The DBP oil absorption of carbon black is a value measured according to JIS K6221.

  The ratio of the specific surface area of carbon black to the DBP oil absorption [specific surface area / DBP oil absorption] is 1.0 or less, preferably 0.70 or less, more preferably 0.50 or less, More preferably, it is 0.30 or less, More preferably, it is 0.20 or less. When [specific surface area / DBP oil absorption] satisfies this range and the average primary particle diameter of carbon black is 20 nm or more, low warpage, weather resistance and weather gloss retention can be further improved.

  The content of carbon black with respect to 100% by mass of the polyamide resin composition is preferably 0.02 to 3.0% by mass. More preferably, it is 0.02-2.0 mass%, More preferably, it is 0.1-1.5 mass%, More preferably, it is 0.3-1.3 mass%, Most preferably, it is 0.4. It is -1.0 mass%. When the carbon black content is within this range, the weather resistance can be further improved without impairing the appearance of the molded product in the polyamide resin composition.

(D) Copper compound The polyamide resin composition of the present invention may be described as (D) a copper compound (hereinafter simply referred to as a copper compound or (D) component) in addition to the components (A) to (C) described above. ) As a copper halide compound, copper thiocyanate, copper nitrate, copper acetate, naphthene copper, copper caprate, copper laurate, copper stearate, acetylacetone copper, copper oxide (I) and copper oxide (II) At least one copper compound may be contained.
These may be used alone or in combination of two or more.

  Among the copper compounds listed above, preferably a copper halide compound (copper fluoride, copper iodide, cuprous bromide, cupric bromide, cuprous chloride, etc.), copper acetate, copper oxide (I ) And copper (II) oxide, more preferably a copper halide compound, still more preferably copper iodide or cuprous bromide. When these are used, a polyamide resin composition that is excellent in low warpage and weather resistance and can effectively suppress metal corrosion of the screw or cylinder during extrusion (hereinafter also simply referred to as metal corrosion) can be obtained.

The content of the copper compound with respect to 100% by mass of the polyamide resin composition is preferably 0.001 to 0.2% by mass, more preferably 0.005 to 0.15% by mass, and still more preferably 0.005. It is -0.1 mass%, More preferably, it is 0.005-0.05 mass%.
When the content of the copper compound in the polyamide resin composition is within the above range, it is possible to further improve the low warpage, weather resistance and weather gloss retention, and effectively suppress copper precipitation and metal corrosion. it can.

  Further, from the viewpoint of improving the low warpage, weather resistance and weather gloss retention of the polyamide resin composition, the content of copper element with respect to 100% by mass of the polyamide resin composition is preferably 0.001% by mass or more, More preferably, it is 0.002 mass% or more, More preferably, it is 0.002-0.05 mass%, More preferably, it is 0.002-0.02 mass%.

(E) Halide of alkali metal and / or alkaline earth metal The polyamide resin composition of the present invention is (E) halogen of alkali metal and / or alkaline earth metal from the viewpoint of improving weather resistance and suppressing metal corrosion. (Hereinafter sometimes simply referred to as halide or (E) component). Examples of (E) halides include, but are not limited to, potassium iodide, potassium bromide, sodium iodide, sodium bromide, lithium iodide, lithium bromide, lithium chloride, calcium iodide. , Calcium bromide, magnesium iodide and magnesium bromide, and mixtures thereof.

  In particular, from the viewpoint of improving weather resistance and suppressing metal corrosion, potassium iodide, potassium bromide, sodium iodide and sodium bromide are preferred, and potassium iodide or potassium bromide is more preferred.

  The content of the halogen element in the polyamide resin composition is preferably 0.02 with respect to 100% by mass of the polyamide resin composition from the viewpoint of improving the low warpage, weather resistance, and weather gloss retention of the polyamide resin composition. It is -4 mass%, More preferably, it is 0.03-1.0 mass%, More preferably, it is 0.03-0.5 mass%. Here, for example, when the component (D) is a copper halide, the halogen element means the total of the halogen element derived from the copper halide and the halogen element derived from the component (E).

  The total ratio of (D) copper compound and (E) halide to 100% by mass of the polyamide resin composition is preferably 0.02 to 5% by mass, more preferably 0.02 to 2% by mass, More preferably, it is 0.03-0.3 mass%. When the total content of component (D) + component (E) is within the above range, low warpage, weather resistance and weather gloss retention can be further improved, and copper precipitation and metal corrosion are effective. Can be suppressed.

(D) The content ratio of the copper compound and (E) halide should be contained so that the molar ratio of the halogen element to the copper element (halogen element / copper element) is 2/1 to 50/1. Is preferable, more preferably 3/1 to 30/1, and still more preferably 3/1 to 20/1.
Here, for example, when the component (D) is a copper halide, the halogen element means the total of the halogen element derived from the copper halide and the halogen element derived from the component (E).

When the molar ratio of the halogen element to the copper element (halogen element / copper element) is 2/1 or more, the weather resistance can be further improved.
On the other hand, when the molar ratio (halogen element / copper element) is 50/1 or less, corrosion of the screw or the like of the molding machine can be prevented without substantially impairing mechanical properties such as toughness.

(F) Crystallization retarder The polyamide resin composition of the present invention has a (F) crystallization retarder (hereinafter simply referred to as crystallization retarder or (F) from the viewpoint of further improving the appearance and mechanical strength of the molded product. In some cases, it may be described as a component).
The crystallization retarder is a substance having an effect of lowering the crystallization temperature of the polyamide resin when blended with the polyamide resin. The crystallization temperature can be determined by a differential scanning calorimetry method (DSC method) based on JIS K7121.

  These crystallization retarders include, but are not limited to, azine dyes and phthalocyanine dyes. Nigrosine is preferable as the azine dye, and copper phthalocyanine dye is preferable as the phthalocyanine dye.

  The content of the crystallization retardant with respect to 100% by mass of the polyamide resin composition is preferably 0.01 to 3.0% by mass. More preferably, it is 0.03-2.0 mass%, More preferably, it is 0.05-1.5 mass%. (A) By setting the content of the crystallization retardant to 0.01% by mass or more with respect to 100% by mass of the polyamide resin, the low warpage and appearance of the molded product of the polyamide resin composition of the present invention are improved, By setting the content to 3.0% by mass or less, a polyamide resin composition having excellent releasability can be obtained.

(G) Lubricant The polyamide resin composition of the present invention further contains (G) a lubricant (hereinafter sometimes simply referred to as a lubricant or (G) component) from the viewpoint of further improving the appearance of the molded product. Also good.
Examples of the lubricant include, but are not limited to, higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts, and polyolefin waxes.
Only one lubricant may be used alone, or two or more lubricants may be used in combination.

The higher fatty acid constituting the higher fatty acid compound refers to a higher aliphatic monocarboxylic acid. In particular, fatty acids having 8 or more carbon atoms are preferred. More preferably, it is a C8-C40 fatty acid.
Higher fatty acids include, but are not limited to, for example, saturated or unsaturated, linear or branched, aliphatic monocarboxylic acids such as stearic acid, palmitic acid, behenic acid, elca Examples include acid, oleic acid, lauric acid, and montanic acid.

A higher fatty acid ester is an ester compound of a higher 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 the higher fatty acid ester include, but are not limited to, stearyl stearate, behenyl behenate, montanic acid-1,3-butanediol ester, montanic acid-trimethylolpropane ester, trimethylolpropane trilaure. Rate, butyl stearate and the like.

A higher fatty acid amide is an amidated product of a higher fatty acid.
Examples of the higher fatty acid amide include, but are not limited to, stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearyl amide, ethylene bis oleyl amide, N-stearyl stearyl amide, N-stearyl erucamide. Examples include amides. 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 higher fatty acid metal salt is a metal salt of the higher fatty acid described above.
Examples of metal elements that form salts with higher 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.

As the higher fatty acid metal salt, a metal salt of montanic acid, a metal salt of behenic acid and a metal salt of stearic acid are preferably used. In particular, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, sodium montanate, montanic acid Calcium, aluminum montanate, zinc montanate, magnesium montanate, sodium behenate, calcium behenate, zinc behenate, calcium laurate, zinc laurate, calcium palmitate, etc., aluminum stearate, zinc stearate, stearin Magnesium acid, calcium montanate, zinc montanate, calcium behenate, and zinc behenate are more preferable, and calcium montanate, zinc montanate, and zinc behenate are more preferable.
These higher fatty acid metal salts may be used alone or in combination of two or more.

Examples of the polyolefin wax include polypropylene wax and polyethylene wax (PE wax).
Polypropylene wax is generally a polypropylene having wax-like properties with a correspondingly low molecular weight. The wax used in the present invention has an average molecular weight (mass average) Mw (using GPC (Gel Permeation Chromatography) and standard polystyrene) of 2000 to 60000, particularly 5000 to 50000, especially 10,000 to 45000. It is preferable.
The softening point of the wax used in the polyamide resin composition of the present invention is calculated by DIN EN 1427 (ring and ball method), and is preferably at least 140 ° C. or higher, more preferably 150 ° C. or higher.

  Preferred products are Licowax® PP, in particular Licowax PP 230 and Licowax VP PP type (Clariant GmbH) and Ceridust® VP 6071 and Hana Corporation, LC 525 N, LC 502 N, LC 502 NC, LC 503 N, LC 503 NC type.

  The polyethylene wax is obtained by radical polymerization of a hydrocarbon wax having an average molecular weight range (mass average) of 2000 to 20000, which is produced by a high pressure method or by a low pressure method in the presence of a metal organic catalyst. At the same time, low molecular weight products with wax properties can be obtained from high molecular weight polyethylene by pyrolysis.

In general, PE waxes are not classified by the production method, but rather are classified by the density in HDPE (high density polyethylene) and LDPE (low density polyethylene), in which case the high pressure method improves the HDPE quality. The resulting low pressure method results in LDPE quality.
The properties of pyrolytic PE wax are similar to those of products by the high pressure method. Also, by changing the implementation of the method, a low density branched type (LDPE) is obtained.
Oxidation with air or oxygen yields highly polar oxidized PE wax (polyethylene wax oxidation product).

  As a starting material for this type of oxidation process, it is possible to use all customary polyolefin waxes, ie polyolefin waxes produced, for example, by the Ziegler-catalyzed or Phillips-catalyzed reaction or by the high-pressure process. The base wax can be taken directly from the polymerization process or can be obtained by thermal decomposition of high molecular weight olefin polymers.

  Suitable waxes include, for example, ethylene and / or C3-C10 alk-1-enes such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. It is derived from. In particular, ethylene or propylene homopolymers or copolymers, particularly preferably ethylene homopolymers or copolymers, are used as polyolefin waxes.

In order to produce the base polyolefin wax, the monomers are homopolymerized or copolymerized with each other in all proportions. Preferred polyolefins based on oxidized waxes have a density of 0.89 to 0.98 g / cm ³ , in particular 0.90 to 0.96 g / cm ³ and 1000 to 40000 g / mol, in particular 2000 to 20000 g / mol. An ethylene homopolymer having a Mw measured by the GPC method in 1,2,4-trichlorobenzene at 135 ° C. using a polyethylene standard or a polypropylene standard.

  Furthermore, ethylene / polyethylene having a total content of structural units derived from one or more alk-1-enes in the copolymer of 0.1-15 mol%, in particular 1-10 mol%, relative to the copolymer, as starting polyolefin C3-C10 alk-1-ene copolymers are suitable. Preferred ethylene / alkene-1-ene copolymers are ethylene / propylene copolymers having a content of structural units derived from propylene in the copolymer of preferably 0.1 to 10 mol%, in particular 1 to 5 mol%, relative to the copolymer. It is. The copolymer generally has a Mw measured by the GPC method as described above of 1000 to 40000 g / mol, in particular 2000 to 20000 g / mol.

Other preferred polyolefins which may be based on oxidized waxes are in the range of 90-98%, pentaden content (isotactic pentaden) measured by ¹³ C-NMR spectroscopy and 1000-40000 g / mol, in particular 2000 ˜20,000 g / mol of isotactic propylene homopolymer having Mw measured by GPC method as described above.

  Furthermore, copolymers of propylene and ethylene and / or C4 to C10 alk-1-enes are also suitable as basic polyolefins. This propylene copolymer usually has a total content of structural units derived from ethylene and / or C4 to C10 alk-1-enes in the copolymer of from 0.1 to 15 mol%, in particular from 1 to 10 mol%, relative to the copolymer. Have Preferred propylene copolymers are propylene / ethylene copolymers having a content of structural units derived from ethylene in the copolymer of from 0.1 to 10 mol%, in particular from 1 to 5 mol%, relative to the copolymer. Propylene copolymers generally have a Mw measured by the GPC method as described above of 1000 to 40000 g / mol, in particular 1000 to 20000 g / mol.

  The acid value of the oxidized wax (according to DIN 53402 or DIN EN D1386) is preferably 11 to 100 [mg KOH / g], in particular 12 to 55 [mg KOH / g], in particular 12 to 30 [mg KOH / g. g]. The saponification number is preferably 11 to 100 [mg KOH / g], in particular 10 to 50 [mg KOH / g], in particular 20 to 30 [mg KOH / g] (according to DIN EN D-1387).

  The content of the lubricant with respect to 100% by mass of the polyamide resin composition is preferably 0.01 to 10% by mass, more preferably 0.03 to 5% by mass, and 0.05 to 2% by mass. More preferably. By setting the content of the lubricant within the above range, a polyamide resin composition that is further excellent in appearance, releasability, mechanical strength, and plasticity can be obtained.

In addition to the components (A) to (G) described above, the polyamide resin composition of the present invention may further contain other components as necessary within the range not impairing the effects of the present invention.
Examples of other components include, but are not limited to, for example, antioxidants, ultraviolet absorbers, heat stabilizers, photodegradation inhibitors, plasticizers, mold release agents, nucleating agents, flame retardants, and colorants. A dyeing agent or a pigment may be added, or another thermoplastic resin may be mixed.
Here, since the other components have greatly different properties, suitable content ratios for each component that hardly impair the effects of the present invention are various. A person skilled in the art can easily set a suitable content for each of the other components described above.

[Production method of polyamide resin composition]
Although it does not restrict | limit as a manufacturing method of the polyamide resin composition of this invention, For example, in the state which melt | dissolved (A) component with the uniaxial or multi-screw extruder, (B) component, (C) component The method of kneading can be used. Among them, a twin screw extruder having an upstream supply port and a downstream supply port is used, and after the component (A) and the component (C) are supplied from the upstream supply port and melted, the downstream supply port is used. It is preferable to use a method of supplying the component (B) and melt-kneading. Moreover, also when using rovings, such as glass fiber and carbon fiber, it can compound by a well-known method.

[Molded body]
The molded article of the present invention is obtained by molding the above-described polyamide resin composition of the present invention, and is obtained, for example, by injection molding the polyamide resin composition.

[Use]
The molded article of the present invention is suitable as various molded articles and parts for automobiles, machine industries, electric / electronics, residential equipment, industrial materials, industrial materials, daily use / household goods, etc. Can be used. In particular, it is suitable for parts for automobiles and residential equipment exposed to the outdoors, and can be suitably used for automobile exterior parts.

Hereinafter, the present invention will be described in detail with specific examples and comparative examples, but the present invention is not limited to the following examples.
Hereinafter, evaluation methods performed in Examples and Comparative Examples will be described.

〔Evaluation method〕
<Low warpage>
Using the injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.), the pellets of the polyamide resin composition obtained in the examples and comparative examples were formed into a flat plate-shaped product having a thickness of 100 × 100 × 2 mm (mirror finish). Manufactured. At that time, the filling time was set to 1 second, the holding pressure time was set to 9 seconds, the cooling time was set to 15 seconds, the mold temperature was 90 ° C, and the molten resin temperature was 290 ° C. After the obtained flat plate molded product was allowed to stand at 23 ° C. and 50% relative humidity for 24 hours, each of the four corners of the molded product raised on the surface plate when one corner was pressed against the surface plate. On the other hand, the distance between the lower surface and the surface plate was measured with a caliper with an accuracy of 0.1 mm. Of the raised corners, the one with the greatest distance from the surface plate was warped. Small warp value is excellent.

<Appearance of molded product>
The pellets of the polyamide resin composition obtained in the examples and comparative examples were manufactured into 80 × 80 × 3 mm thick mirror plate test pieces using an injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.). At that time, the filling time was set to 1 second, the pressure holding time 9 seconds, the cooling time 15 seconds, and the molten resin temperature 290 ° C. Moreover, the mold temperature was set as follows according to the Example. Examples 1-9, Comparative Examples 1-9: 90 ° C, Examples 10-11, Comparative Example 10: 130 ° C. The surface gloss of the obtained flat plate test piece was measured at an incident angle of 60 degrees using a gloss meter (VG7000: manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS Z8741.

<Weatherproof gloss retention>
The flat molded piece whose surface gloss was measured as described above was compliant with ISO 4894-2 using a xenon arc type accelerated weathering tester (Ci4000: manufactured by Atlas Co., Ltd.), black panel temperature 63 ° C., water spraying time 18 minutes, water The accelerated weathering test was conducted with a cycle of 102 minutes spray stop time. The surface gloss of the flat plate test piece after 1,000 hours of test time was measured, and the gloss retention was calculated.

<Weather discoloration>
The pellets of the polyamide resin compositions obtained in the examples and comparative examples were 80 × 80 × 3 mm thick (single-sided textured processing: Yoko Tanazawa) using an injection molding machine (PS-40E: manufactured by Nissei Plastic Co., Ltd.). TH113) flat plate test piece. At that time, the filling time was set to 1 second, the pressure holding time 9 seconds, the cooling time 15 seconds, and the molten resin temperature 290 ° C. Moreover, the mold temperature was set as follows according to the Example. Examples 1-9 and Comparative Examples 1-9: 90 ° C, Examples 10-11 and Comparative Example 10: 130 ° C. The textured surface of the obtained flat plate test piece was used as the test surface, and a xenon arc type accelerated weathering tester (Ci4000: manufactured by Atlas Co.) was used in accordance with ISO 4894-2, with a black panel temperature of 63 ° C. and a water spray time of 18 minutes. The accelerated weathering test was carried out with a water spray stop time of 102 minutes. Before the test, the plate test pieces after 1,000 hours and after 1,500 hours were measured for color tone according to JIS Z8722 using a color difference meter (SE6000: manufactured by Nippon Denshoku Industries Co., Ltd.) A change in color tone ΔE after the test was obtained from before the test.

<Viscosity of formic acid solution at 25 ° C>
The measurement was performed according to Appendix JA of JIS-K6920-2. For the polyamide resins used in the examples and comparative examples, a polymer solution ((ratio of polyamide 5.5 g) / (90% formic acid 50 mL)) was prepared using 90% formic acid, and the temperature was 25 ° C. It was measured.

〔raw materials〕
(A) Polyamide resin (PA)
(A-1) Polyamide 66 / 6I, polyamide of Production Example 1 below Formic acid solution viscosity at 25 ° C .: 27
Structural unit having an aromatic structure in 100% by mass of polyamide resin: 20% by mass
(A-2) Polyamide 6I / 6T, EMS Co., Ltd. polyamide “Grivory G21”
Structural unit having an aromatic structure in 100% by mass of polyamide resin: 100% by mass
(A-3) Polyamide MXD6, Polyamide of Production Example 2 below: Structural unit having an aromatic structure in 100% by mass of polyamide resin: 48% by mass
(A-4) Polyamide 66, polyamide “1300” manufactured by Asahi Kasei Chemicals Corporation
Structural unit having an aromatic structure in 100% by mass of polyamide resin: 0% by mass
(A-5) Polyamide 6, Polyamide “K122” manufactured by DSM Corporation
Structural unit having an aromatic structure in 100% by mass of polyamide resin: 0% by mass

(B) Glass fiber (hereinafter abbreviated as GF) manufactured by Nippon Electric Glass Co., Ltd. ECS03T-275H

(C) Carbon black (CB)
(C-1) Carbon black showing the following characteristics Average primary particle size: 85 nm,
Specific surface area / DBP oil absorption: 0.18
Nitrogen adsorption specific surface ^area: 20m 2 / g, DBP oil ^absorption: 110 cm 3/100 g
(C-2) Carbon black showing the following characteristics Average primary particle size: 55 nm,
Specific surface area / DBP oil absorption: 0.25
Nitrogen adsorption specific surface ^area: 32m 2 / g, DBP oil ^absorption: 130 cm 3/100 g
(C-3) Carbon black having the following characteristics Average primary particle size: 29 nm
Specific surface area / DBP oil absorption: 0.25
Nitrogen adsorption specific surface ^area: 110m 2 / g, DBP oil ^absorption: 440 cm 3/100 g
(C-4) Carbon black showing the following characteristics Average primary particle size: 30 nm,
Specific surface area / DBP oil absorption: 0.65
Nitrogen adsorption specific surface ^area: 74m 2 / g, DBP oil ^absorption: 113cm 3 / 100g

(C-5) Carbon black having the following characteristics Average primary particle size: 24 nm,
Specific surface area / DBP oil absorption: 1.8
Nitrogen adsorption specific surface ^area: 115m 2 / g, DBP oil ^absorption: 65cm 3 / 100g
(C-6) Carbon black showing the following characteristics Average primary particle size: 14 nm,
Specific surface area / DBP oil absorption: 0.74
Nitrogen adsorption specific surface ^area: 460m 2 / g, DBP oil ^absorption: 620 cm 3/100 g
(C-7) Carbon black showing the following characteristics Average primary particle size: 19 nm,
Specific surface area / DBP oil absorption: 1.2
Nitrogen adsorption specific surface ^area: 140m 2 / g, DBP oil ^absorption: 114 cm 3/100 g

(D) Copper iodide (hereinafter abbreviated as CuI) reagent manufactured by Wako Pure Chemical Industries, Ltd. (E) Potassium iodide (hereinafter abbreviated as KI) reagent manufactured by Wako Pure Chemical Industries, Ltd. (F) Crystallization retarder Copper Phthalocyanine dyes: C.I. I. Solvent Blue 67
Azine dyes: Nigrosine, NUBIAN (registered trademark) BLACK TH-807 manufactured by Orient Chemical Industries, Ltd.
(G) Lubricant Montanic acid metal salt: Recommont NaV101 manufactured by Clariant

[Production Example 1]
Add equimolar salts of hexamethylene diamine and adipic acid, and equimolar salts of hexamethylene diamine and isophthalic acid at a mass ratio of 80:20, respectively, add the same amount of pure water as all the raw materials added, After sufficiently purging with nitrogen, heating was started with stirring. The final pressure was 270 ° C. while adjusting the internal pressure of the can to a maximum of 2.0 MPa (G), and the polymer discharged into the water bath was pelletized with a strand cutter. The proportion of the structural unit having an aromatic structure in 100% by mass of the obtained polyamide resin was 20% by mass, and the formic acid solution viscosity at 25 ° C .: 27.

[Production Example 2]
In a separable flask having an internal volume of 2 L equipped with a stirrer, a partial condenser, a thermometer, a dropping funnel, and a nitrogen gas introduction tube, 600 g of adipic acid weighed precisely was placed, thoroughly purged with nitrogen, and then under a small amount of nitrogen stream After heating to 190 ° C. and uniformly melting, the mixture was stirred as it was for 20 minutes, and 562 g of metaxylylenediamine was added dropwise over 120 minutes with stirring. During this time, the reaction temperature was continuously raised to 250 ° C. Condensed water produced by the dropwise addition of diamine was removed from the system through a partial condenser and a full condenser. After completion of the diamine addition, the reaction was continued for 60 minutes at an internal temperature of 258 ° C. The proportion of structural units having an aromatic structure in 100% by mass of the obtained polyamide resin was 48% by mass.

[Examples 1 to 11], [Comparative Examples 1 to 10]
L / D (extruder cylinder length / extruder cylinder diameter) having an upstream supply port in the first barrel from the upstream side of the extruder and a downstream supply port in the ninth barrel = 48 (number of barrels: 12) twin screw extruder [ZSK-26MC: manufactured by Coperion (Germany)] was used. In the twin-screw extruder, the temperature from the upstream supply port to the die was set to 300 ° C., screw rotation speed 250 rpm, and discharge rate 25 kg / hour.

  Under such conditions, according to the ratio described in the upper column of Tables 1 to 3, from the upstream supply port, (A) PA, (C) CB, (D) CuI, (E) KI, (F) crystals The retarder and (G) lubricant were supplied, and (B) GF was supplied from the downstream supply port. And the pellet of the polyamide resin composition was manufactured by melt-kneading these. The obtained polyamide resin composition was molded at the above melt resin temperature and mold temperature, and the appearance of the molded product, weather gloss retention, weather discoloration resistance, and tensile strength were evaluated.

  These evaluation (counting) results are shown in Table 1, Table 2, and Table 3 below. In Tables 1, 2, and 3, the lower warpage indicates that the lower the numerical value, the better the low warpage. The larger the numerical value of the molded product appearance (surface gloss), the better the molded product appearance. The larger the numerical value of the weather gloss retention, the smaller the numerical value of the color tone change ΔE, the better the weather resistance.

  As shown in Table 1, (A) Polyamide resin contains aromatic polyamide, (C) Carbon black has a specific surface area / DBP oil absorption of 1.0 or less, and an average primary particle size of 20 nm or more. In Nos. 1 to 4, a polyamide resin composition having low warpage and good appearance of the molded product and excellent weather resistance gloss retention and weather resistance was obtained. On the other hand, (A) even if aromatic polyamide is included in the polyamide resin, (C) the specific surface area / DBP oil absorption of carbon black exceeds 1.0, or (C) the average primary particle diameter of carbon black Comparative Examples 1 to 3 having a thickness of less than 20 nm were inferior to the examples in terms of low warpage, appearance, weather gloss retention and weather resistance. In addition, as in Comparative Examples 4 to 6, when (A) the polyamide resin did not contain an aromatic polyamide, the low warpage, appearance, weather gloss retention and weather resistance were inferior to those of the Examples. More specifically, when (A) the polyamide resin does not contain an aromatic polyamide, the specific surface area / DBP oil absorption is 1 which showed excellent low warpage, appearance, weather gloss retention and weather resistance in Example 1. Even when (C) carbon black having an average primary particle diameter of 20 nm or more was used, as shown in Comparative Example 4, the low warpage, appearance, weather-resistant gloss retention, and weather resistance were inferior.

  Further, as shown in Table 2, (A) the polyamide resin contains an aromatic polyamide, (C) the specific surface area / DBP oil absorption of carbon black is 1.0 or less, and the average primary particle size is 20 nm or more. In Examples 5 to 8, regardless of whether or not (D) a copper compound, (E) a halide, and (F) a crystallization retarder are contained, all have excellent low warpage, appearance, weather-resistant gloss retention, and weather resistance. showed that. On the other hand, when (D) a copper compound and (E) a halide are not included, and (C) the specific surface area / DBP oil absorption of carbon black exceeds 1.0, as in Comparative Example 7 (A ) Even if an aromatic polyamide was included in the polyamide resin, the low warpage, appearance, weather gloss retention and weather resistance were poor. When (D) copper compound, (E) halide is not included, and (A) the polyamide resin does not contain aromatic polyamide, (C) carbon black has a specific surface area / DBP oil absorption of 1.0 or less, and Even when the average primary particle size was 20 nm or more, the low warpage, appearance, weather gloss retention and weather resistance were inferior as in Comparative Example 8. Since Example 7 has a higher GF content than the other examples, Example 8 did not contain a crystallization retarder (F), so the appearance of the molded product was slightly lowered, but low warpage and weather resistance. Sex was not inferior to other examples.

  Examples 9 to 11 shown in Table 3 are cases where (A) the polyamide resin was changed, but when (A) the polyamide resin contains an aromatic polyamide, (C) carbon black as in Example 10 When the specific surface area / DBP oil absorption is 1.0 or less and the average primary particle diameter is 20 nm or more, low warpage, appearance, weather gloss retention and weather resistance were excellent. Further, as in Examples 9 and 11, if the specific surface area / DBP oil absorption of (C) carbon black is 1.0 or less and the average primary particle diameter is 20 nm or more, it is a blend with an aliphatic amide. Were found to be excellent in low warpage, appearance, weather gloss retention and weather resistance. Conversely, as in Comparative Examples 9 and 10, even though (A) the polyamide resin contains an aromatic polyamide, (C) the specific surface area / DBP oil absorption of carbon black is more than 1.0, and the average primary particle size is It was found that the thickness was less than 20 nm, the low warpage, appearance, weather gloss retention and weather resistance were poor.

  From the above, it has been found that the polyamide resin composition of the present invention is excellent in low warpage and weather resistance, and can provide a molded product having a better appearance.

  The polyamide resin composition of the present invention has industrial applicability as a material for molded articles that require a high level of low warpage, weather resistance, and appearance, such as automobile exterior parts and housing-related parts.

Claims (16)

(A) a polyamide resin;
(B) an inorganic filler;
(C) carbon black;
A polyamide resin composition comprising:
At least a part of the (A) polyamide resin is (a1) an aromatic polyamide,
The (C) carbon black has an average primary particle diameter of 20 nm or more, and a specific surface area / DBP oil absorption amount which is a ratio of a specific surface area to a DBP oil absorption amount is 1.0 or less.   2. The polyamide resin composition according to claim 1, wherein the proportion of the structural unit having an aromatic structure with respect to 100 mass% of all the structural units constituting the (A) polyamide resin is 5 to 100 mass%.   The (A) polyamide resin contains (a2) an aliphatic polyamide as an optional component, and the ratio of the (a1) aromatic polyamide to 100% by mass of the (A) polyamide resin is 10% by mass to 100% by mass, The polyamide resin composition according to claim 1 or 2, wherein the proportion of the (a2) aliphatic polyamide is 0% by mass or more and 90% by mass or less.   The (a1) aromatic polyamide contains at least one selected from polyamide 4T, polyamide 4I, polyamide 6T, polyamide 6I, polyamide MXD6, polyamide MXD10, polyamide MXD12, polyamide PXD6, polyamide PXD10 and polyamide PXD12 as a constituent component Item 4. The polyamide resin composition according to item 1, 2 or 3.   The (a2) aliphatic polyamide constitutes polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 410, polyamide 412, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012 and at least one of them. It is at least 1 sort (s) chosen from the copolyamide included as a component, The polyamide resin composition as described in any one of Claims 1-4.   The polyamide resin composition according to any one of claims 1 to 5, wherein the (C) carbon black has an average primary particle size of 35 nm or more. The specific surface area of said (C) carbon black is 100 m < ² > / g or less, The polyamide resin composition as described in any one of Claims 1-6. Wherein (C) the polyamide resin composition as claimed in any one claims 1 to 7 DBP oil absorption of the carbon black is 100 cm ^3/100 g or more.   Further, (D) a copper compound is contained, and the (D) copper compound is a copper halide compound, copper thiocyanate, copper nitrate, copper acetate, naphthene copper, copper caprate, copper laurate, copper stearate, acetylacetone copper The polyamide resin composition according to claim 1, wherein the polyamide resin composition is at least one selected from copper oxide (I) and copper oxide (II).   The polyamide resin composition according to any one of claims 1 to 9, further comprising (E) a halide of an alkali metal and / or an alkaline earth metal.   Furthermore, the polyamide resin composition as described in any one of Claims 1-10 containing (F) crystallization retarder.   The polyamide resin composition according to claim 11, wherein the (F) crystallization retarder is an azine dye or a phthalocyanine dye.   The composition further comprises (G) a lubricant, and the (G) lubricant is at least one selected from higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts and polyolefin waxes. The polyamide resin composition described in 1.   The ratio of the said (B) inorganic filler with respect to 100 mass% of polyamide resin compositions is 30 mass% or more and 70 mass% or less, The polyamide resin composition as described in any one of Claims 1-13.   The molded object formed by shape | molding the polyamide resin composition as described in any one of Claims 1-14.   The molded article according to claim 15, which is an automobile exterior part.