JP7311338B2 - Method for producing polyamide resin composition and molded article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyamide resin composition and a molded article.

In recent years, with the demand for weight reduction of automobiles, resin parts are frequently used. In particular, the use of polyamide resins, which are excellent in heat resistance, chemical resistance, and moldability, is increasing for engine peripheral parts. Conventionally, as a duct part connected to an intake and exhaust system of an engine, primary moldings using polyamide 66 obtained by injection molding are welded together and used as a single part. However, the design of the shape that considers the welding of the primary molded body can sufficiently respond to simple shapes, but on the other hand, it cannot sufficiently respond to complicated shapes, and the degree of freedom in design is limited. .

Against this background, molding of various parts by blow molding has been studied. Blow molding is usually used to form a cylindrical parison, for example, and then blow air into it to obtain a molded article that conforms to the shape of the mold. In addition, since there is no need to use a plurality of primary molded bodies and the process of welding is not required, a final molded product can be obtained without joining parts.

Performances required for blow molding materials include parison drawdown resistance and stretchability. Stretchability is important when the extruded parison is sandwiched between molds and molded into a desired shape. A factor that affects stretchability is the rate of solidification of the parison. If the material hardens quickly, it will cool and harden before the parison is stretched into the desired shape, preventing complete molding. Therefore, it is necessary to maintain the molten state until the completion of blowing.

BACKGROUND ART Conventionally, as polyamide resins for blow molding, alloy resins mainly composed of polyamide 6, polyamide 66, etc. have been used (Patent Document 1). Among them, polyamide 6 has a lower crystallinity than polyamide 66 and crystalline semi-aromatic polyamide, so that the parison is difficult to harden, and is particularly suitable for blow molding.

On the other hand, attempts have been made to control crystallinity and improve blow moldability by mixing even highly crystalline polyamide resins such as polyamide 66 with amorphous polyamides (patent Reference 2).

JP 2007-204675 A Japanese Patent Application Laid-Open No. 2009-132908

However, in the techniques described in Patent Documents 1 and 2, even with a blow-moldable polyamide resin composition, blow moldability, such as wall thickness uniformity, surface appearance, and heat resistance when formed into a molded product It is difficult to sufficiently improve aging resistance and chemical resistance.

The present invention has been made in view of the above circumstances, and uses a polyamide resin composition having excellent blow moldability, heat aging resistance and chemical resistance when molded, and the polyamide resin composition. A method for manufacturing a molded article is provided.

That is, the present invention includes the following aspects.
The polyamide resin composition according to the first aspect of the present invention comprises (A-1) polyamide 66, (A-2) a polyamide resin other than polyamide 66, (B) ethylene-maleic acid derivative random copolymer and E /X/Y terpolymer (wherein E is ethylene, X is vinyl acetate, and one or more monomers selected from the group consisting of (meth)acrylic acid and derivatives thereof, Y is maleic anhydride A polyamide resin composition containing one or more copolymers selected from the group consisting of derivatives) , wherein the content of ethylene units with respect to the total mass of all structural units constituting the copolymer is 85% by mass or more and 97% by mass or less, and from the group consisting of maleic acid monoester, maleic acid diester, fumaric acid monoester, and fumaric acid diester with respect to the total mass of all structural units constituting the copolymer The content of one or more selected maleic acid derivative units is 3% by mass or more and 15% by mass or less, and the melting point of the (A-2) polyamide resin other than polyamide 66 is 210° C. or more and 340° C. or less, The mass ratio (A-2)/(A-1) of the polyamide resin other than the (A-2) polyamide 66 to the (A-1) polyamide 66 is 5/95 or more and 95/5 or less, and the copolymer weight The combined content is 5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the total mass of (A-1) polyamide 66 and (A-2) polyamide resin other than polyamide 66.

Among polyamide resins other than (A-1) polyamide 66 and (A-2) polyamide resins other than polyamide 66, tan δ measured by a rotary rheometer at melting point +10° C. of the polyamide resin having the highest melting point satisfies the following formula: good too.

(In the formula, tan δ (1) represents tan δ when measured at an angular velocity of 1 rad/sec, and tan δ (100) represents tan δ when measured at an angular velocity of 100 rad/sec.)

The content of the (B) ethylene-maleic acid derivative random copolymer is 5 parts per 100 parts by mass of the total weight of the polyamide resin other than the (A-1) polyamide 66 and the (A-2) polyamide resin other than the polyamide 66. It may be more than or equal to 20 parts by mass or less.

The (A-2) polyamide resin other than polyamide 66 may be one or more selected from the group consisting of polyamide 6, polyamide 610, and polyamide 612.

The (A-2) polyamide resin other than polyamide 66 may be polyamide 6 or polyamide 612.

The polyamide resin composition according to the first aspect may further contain (C) an inorganic filler.

The polyamide resin composition according to the first aspect further contains (D) an alkali metal salt, and the content of the (D) alkali metal salt is equal to the (A-1) polyamide 66 and the (A-2) It may be 0.01 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the total mass of polyamide resins other than polyamide 66.

In the polyamide resin composition according to the first aspect, the (D) alkali metal salt may be sodium carbonate or sodium hydrogen carbonate.

The polyamide resin composition according to the first aspect may further contain (E) a neutralizing agent.

The polyamide resin composition according to the first aspect further contains (F) elemental iron, and the content of (F) elemental iron is the (A-1) polyamide 66 and the (A-2) polyamide 66 It may be 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total mass of the other polyamide resins.

The polyamide resin composition according to the first aspect further contains (G) a copper halide, and (H) one or more halides selected from the group consisting of alkali metal halides and alkaline earth metal halides. may contain.

A method for producing a molded article according to the second aspect of the present invention is a method of molding the polyamide resin composition according to the first aspect by blow molding.
The molded article may have a hollow shape.
The molded article may be a material part for automobiles.
The molded article may be a turbo duct.
The molded article may be a battery cooling pipe.

According to the polyamide resin composition of the above aspect, it is possible to provide a polyamide resin composition which is excellent in blow moldability, heat aging resistance and chemical resistance when molded. The method for producing a molded article according to the above aspect is a method using the polyamide resin composition, and a molded article having excellent heat aging resistance and chemical resistance can be obtained.

EMBODIMENT OF THE INVENTION Hereinafter, the form (only henceforth "this embodiment") for implementing this invention is demonstrated in detail.
The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.

As used herein, the term "polyamide" means a polymer having an amide (--NHCO--) group in its main chain.

<<Polyamide resin composition>>
The polyamide resin composition of the present embodiment includes (A-1) polyamide 66 (hereinafter sometimes referred to as "(A-1) component") and (A-2) a polyamide resin other than polyamide 66 (hereinafter , (A) polyamide resin (hereinafter sometimes referred to as "(A) component") consisting of (sometimes referred to as "(A-2) component"), and (B) ethylene-maleic acid derivative random copolymer coalescence (hereinafter sometimes referred to as "(B) component");

(B) The content of ethylene units is 85% by mass or more and 97% by mass or less, preferably 88% by mass or more and 95% by mass or less, relative to the total mass of all structural units constituting the ethylene-maleic acid derivative random copolymer. , more preferably 90% by mass or more and 94% by mass or less.

(B) The content of maleic acid derivative units is 3% by mass or more and 15% by mass or less, and 5% by mass or more and 12% by mass or less, relative to the total mass of all structural units constituting the ethylene-maleic acid derivative random copolymer. is preferable, and 6% by mass or more and 10% by mass or less is more preferable.

Examples of maleic acid derivatives include maleic acid monoesters, maleic acid diesters, fumaric acid monoesters, fumaric acid diesters, and methyl maleic anhydride. These maleic acid derivatives may be used singly or in combination of two or more.

As used herein, the term "structural unit" means a structure resulting from one molecule of a monomer in a structure constituting a polyamide resin or an ethylene-maleic acid derivative random copolymer. For example, a maleic acid derivative unit indicates a structure resulting from one molecule of a maleic acid derivative in an ethylene-maleic acid derivative random copolymer. Further, the ethylene unit indicates a structure resulting from one molecule of ethylene in the ethylene-maleic acid derivative random copolymer. The structural unit may be a unit directly formed by a (co)polymerization reaction of monomers, or may be a unit in which a part of the unit is converted to another structure by treating the (co)polymer. There may be.

By having the above configuration, the polyamide resin composition of the present embodiment can appropriately crosslink the component (A) (component (A-1) and component (A-2)) and component (B). , blow moldability, and a polyamide resin composition that is excellent in heat aging resistance and chemical resistance when formed into a molded product.
Each component of the polyamide resin composition of the present embodiment will be described in detail below.

<(A) Polyamide resin>
The polyamide resin composition of the present embodiment contains (A-1) polyamide 66 and (A-2) a polyamide resin other than polyamide 66 as (A) polyamide resin.

[(A-1) Polyamide 66]
"Polyamide 66" is a polyamide resin obtained by polymerizing hexamethylenediamine as a diamine and adipic acid as a dicarboxylic acid as polymerization monomers, and having a unit composed of hexamethylenediamine and a unit composed of adipic acid. .

The terminal amino group concentration of (A-1) Polyamide 66 is not particularly limited, but is preferably 10 μmol/g or more because the reaction with (B) ethylene-maleic acid derivative random copolymer is easy. (A-1) The upper limit of the terminal amino group concentration of polyamide 66 is not particularly limited, but can be, for example, 100 μmol/g.

(A-1) The terminal carboxyl group concentration of polyamide 66 is not particularly limited, but is preferably 100 μmol/g or less because of excellent heat aging resistance and hydrolysis resistance. (A-1) The lower limit of the terminal carboxyl group concentration of polyamide 66 is not particularly limited, but can be, for example, 10 μmol/g.

The terminal group concentration of (A-1) Polyamide 66 can be measured by neutralization titration. Specifically, it can be measured by the method described in the examples below.

(A-1) The sulfuric acid relative viscosity of polyamide 66 is preferably 1.8 or more and 4.5 or less, more preferably 2.1 or more and 4.0 or less. When the sulfuric acid relative viscosity is at least the above lower limit, there is a tendency to obtain a polyamide resin composition having excellent blow moldability and mechanical properties when molded. On the other hand, when the relative viscosity of sulfuric acid is equal to or less than the above upper limit, there is a tendency that a polyamide resin composition having excellent appearance of molded articles and excellent productivity can be obtained.
In addition, the sulfuric acid relative viscosity can be measured by a method based on JIS K 6920.
The sulfuric acid relative viscosity can be controlled by adjusting the pressure during polymerization of (A-1) Polyamide 66.

(A-1) Polyamide 66 preferably has a melting point of 250° C. or higher and 270° C. or lower. When the melting point is at least the above lower limit, the heat resistance of the molded article is further improved. tend to be effectively suppressed.
The melting point can be measured by a method conforming to JIS-K7121. As a measuring device, for example, Diamond DSC manufactured by PERKIN-ELMER can be used.
The melting point can be controlled by adjusting the monomers constituting (A-1) Polyamide 66.

(A-1) Polyamide 66 may use a diamine other than hexamethylenediamine, a dicarboxylic acid other than adipic acid, or the like as a polymerization monomer within a range that does not impair the effects of the present embodiment. Examples of such polymerizable monomers include amino acids, lactams, diamines, dicarboxylic acids and the like. A polyamide homopolymer obtained by polymerizing one kind of these polymerization monomers alone may be used, or a copolymer obtained by polymerizing two or more kinds thereof in combination may be used.

Examples of amino acids include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, para-aminomethylbenzoic acid and the like.

Lactams include, for example, ε-caprolactam and ω-laurolactam.

Diamines can be classified as aliphatic diamines, aromatic diamines and cycloaliphatic diamines.

Aliphatic diamines include, for example, tetramethylenediamine, pentamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- or 2,4- , 4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, and the like.

Examples of aromatic diamines include meta-xylylenediamine and para-xylylenediamine.

Examples of alicyclic diamines include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, aminoethylpiperazine and the like.

Dicarboxylic acids can be classified into aliphatic dicarboxylic acids, aromatic dicarboxylic acids and alicyclic dicarboxylic acids.

Examples of aliphatic dicarboxylic acids include sebacic acid, suberic acid, azelaic acid, dodecanedioic acid and the like.

Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydro terephthalic acid, hexahydroisophthalic acid and the like.

Alicyclic dicarboxylic acids include, for example, 1,2-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

(A-1) The method for producing polyamide 66 is not particularly limited, and it can be produced by a known production method. For example, hexamethylenediamine and adipic acid, optionally a polymerization monomer other than hexamethylenediamine and adipic acid, a solvent or water, a catalyst, and a method of polymerizing by melting and heating components for adjusting the polymerization, etc. Examples include a solid phase polymerization method in which a thermally polymerized prepolymer is heated below its melting point to increase the degree of polymerization in a solid state, and an extrusion polymerization method in which the prepolymer is melted through an extruder to increase the degree of polymerization. These polymerization methods may be batch production or continuous production.

[(A-2) Polyamide resin other than polyamide 66]
(A-2) The polyamide resin other than polyamide 66 is not limited to the following, but for example, a polyamide resin obtained by condensation polymerization of a diamine and a dicarboxylic acid, a polyamide resin obtained by ring-opening polymerization of a lactam, Examples include polyamide resins obtained by self-condensation of aminocarboxylic acids, and copolymers obtained by copolymerizing two or more monomers constituting these polyamide resins. These (A-2) polyamide resins other than polyamide 66 may be used singly or in combination of two or more.

(A-2) Polymerized monomers that are raw materials for polyamide resins other than polyamide 66 are described in detail below.

(diamine)
Examples of diamines include, but are not limited to, aliphatic diamines, alicyclic diamines, and aromatic diamines.

The aliphatic diamine may be a linear saturated aliphatic diamine or a branched saturated aliphatic diamine. Branched saturated aliphatic diamines include, for example, diamines having substituents branched from the main chain.

The linear saturated aliphatic diamine preferably has 2 to 20 carbon atoms, and examples thereof include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, and the like.

The branched saturated aliphatic diamine preferably has 3 to 20 carbon atoms, such as 2-methylpentamethylenediamine (also referred to as "2-methyl-1,5-diaminopentane"), 2,2,4 -trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyloctamethylenediamine, 2,4-dimethyloctamethylenediamine and the like.

Alicyclic diamines (also referred to as alicyclic diamines) include, but are not limited to, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and 1,3-cyclopentanediamine. etc.

Examples of aromatic diamines include, but are not limited to, meta-xylylenediamine, para-xylylenediamine, meta-phenylenediamine, ortho-phenylenediamine, and para-phenylenediamine.

These diamines may be used individually by 1 type, and may be used in combination of 2 or more types.

(Dicarboxylic acid)
Examples of dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids.

The aliphatic dicarboxylic acid may be a linear saturated aliphatic dicarboxylic acid or a branched saturated aliphatic dicarboxylic acid, preferably having 3 or more and 20 or less carbon atoms. Examples of such aliphatic dicarboxylic acids include, but are not limited to, malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2, 2-diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid, diglycolic acid and the like.

The number of carbon atoms in the alicyclic structure of the alicyclic dicarboxylic acid (also referred to as alicyclic dicarboxylic acid) is not particularly limited, but from the viewpoint of the balance between the water absorption and crystallinity of the obtained component (A-2) , preferably 3 or more and 10 or less, more preferably 5 or more and 10 or less.

The alicyclic dicarboxylic acid may be unsubstituted or may have a substituent. As the substituent, an alkyl group having 1 to 4 carbon atoms is preferable. Examples of substituents include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group and the like.

Examples of such alicyclic dicarboxylic acids include, but are not limited to, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, and the like. be done.

Examples of aromatic dicarboxylic acids include, but are not limited to, unsubstituted or substituted aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of substituents include, but are not limited to, alkyl groups having 1 to 6 carbon atoms, aryl groups having 6 to 12 carbon atoms, arylalkyl groups having 7 to 20 carbon atoms, and halogen groups. , an alkylsilyl group having 3 to 10 carbon atoms, a sulfonic acid group, a group having a sulfonate, and the like. Halogen groups include, for example, a chloro group and a bromo group. Examples of salts constituting groups having sulfonate include sodium salts and the like.

Examples of such aromatic dicarboxylic acids include, but are not limited to, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid.

These dicarboxylic acids may be used individually by 1 type, and may be used in combination of 2 or more types.

Moreover, in addition to these dicarboxylic acids, a polyvalent carboxylic acid having a valence of 3 or more may be used as long as the effects of the present embodiment are not impaired. Examples of trivalent or higher polyvalent carboxylic acids include, but are not limited to, trimellitic acid, trimesic acid, and pyromellitic acid.

(lactam)
Examples of lactams include, but are not limited to, butyrolactam, pivalolactam, ε-caprolactam, caprylollactam, enantholactam, undecanolactam, laurolactam (dodecanolactam), and the like. Among them, from the viewpoint of toughness, ε-caprolactam or laurolactam is preferred, and ε-caprolactam is more preferred.
These lactams may be used singly or in combination of two or more.

(aminocarboxylic acid)
Examples of the aminocarboxylic acid include, but are not limited to, the above-mentioned lactam ring-opened compounds, more specifically ω-aminocarboxylic acids, α,ω-aminocarboxylic acids, and the like. .

The aminocarboxylic acid may be either an aliphatic aminocarboxylic acid or an aromatic aminocarboxylic acid. Examples of aromatic aminocarboxylic acids include, but are not limited to, para-aminomethylbenzoic acid.

From the viewpoint of increasing the crystallinity, the aminocarboxylic acid is preferably a linear or branched saturated aliphatic aminocarboxylic acid having 4 or more and 14 or less carbon atoms, which is substituted with an amino group at the ω-position. . Specific examples of preferred aminocarboxylic acids include, but are not limited to, 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like.

These aminocarboxylic acids may be used individually by 1 type, and may be used in combination of 2 or more types.

(A-2) Polyamide resins other than polyamide 66 are not limited to the following, but examples include polyamide 4 (polyα-pyrrolidone), polyamide 6 (polycaproamide), and polyamide 11 (polyundecaneamide). , polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide ), polyamide 116 (polyundecamethylene adipamide), polyamide TMHT (trimethylhexamethylene terephthalamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 2Me-5T (poly 2-methylpentamethylene terephthalamide), polyamide 9T (polynonamethylene terephthalamide), 2Me-8T (poly 2-methyloctamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), polyamide 6C (polyhexamethylenecyclohexanedicarboxamide), polyamide 2Me-5C (poly 2-methylpentamethylenecyclohexanedicarboxamide), polyamide 9C (polynonamethylenecyclohexanedicarboxamide), 2Me-8C (poly 2-methyloctamethylenecyclohexanedicarboxamide), polyamide PACM12 (polybis(4-aminocyclohexyl)methandodecanamide) , polyamide dimethyl PACM12 (polybis(3-methyl-aminocyclohexyl)methandodecanamide, polyamide MXD6 (polymetaxylylene adipamide), polyamide 10T (polydecamethylene terephthalamide), polyamide 11T (polyundecamethylene terephthalamide), Polyamide 12T (polydodecamethylene terephthalamide), polyamide 10C (polydodecamethylenecyclohexanedicarboxamide), polyamide 11C (polyundecamethylenecyclohexanedicarboxamide), polyamide 12C (polydodecamethylenecyclohexanedicarboxamide) and the like.
In addition, "Me" shows a methyl group.

Among them, (A-2) polyamide resins other than polyamide 66 include polyamide 46 (polytetramethylene adipamide) and polyamide 6 from the viewpoint of heat aging resistance, mechanical properties, and chemical resistance when formed into molded articles. (polycaproamide), polyamide 610, polyamide 612, polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonanemethylene terephthalamide), and polyamide 6I (polyhexamethylene isophthalamide). The above polyamide resins are preferred. When two or more of the above polyamide resins are used, a mixture of these polymers may be used, or a copolymer containing these polymers as structural units may be used.

(A-2) As a polyamide resin other than polyamide 66, polyamide 6 (polycaproamide) is most preferable from the viewpoint of improving heat aging resistance, and polyamide 610 or polyamide 612 is particularly preferable from the viewpoint of improving chemical resistance. Preferred, polyamide 612 being most preferred.

(A-2) The lower limit of the melting point of the polyamide resin other than polyamide 66 is not particularly limited, but is preferably 200°C, more preferably 210°C, and even more preferably 220°C. On the other hand, the upper limit of the melting point is preferably 340°C. That is, the melting point of the (A-2) polyamide resin other than polyamide 66 is preferably 200° C. or higher and 340° C. or lower, more preferably 210° C. or higher and 340° C. or lower, and even more preferably 220° C. or higher and 340° C. or lower. When the melting point is equal to or higher than the above lower limit, there is a tendency that the heat aging resistance of a molded article is further improved. On the other hand, when the melting point is equal to or lower than the above upper limit, thermal decomposition and deterioration during melt processing of the polyamide resin composition tend to be more effectively suppressed.
The melting point can be measured according to JIS-K7121. As a measuring device, for example, Diamond DSC manufactured by PERKIN-ELMER can be used.
The melting point can be controlled by adjusting the monomers constituting the polyamide resin (A-2) other than polyamide 66.

(A-2) The sulfuric acid relative viscosity of the polyamide resin other than polyamide 66 is preferably 1.8 or more and 4.5 or less, more preferably 2.1 or more and 4.0 or less. When the sulfuric acid relative viscosity is at least the above lower limit, there is a tendency to obtain a polyamide resin composition having excellent blow moldability and mechanical properties when molded. On the other hand, when the relative viscosity of sulfuric acid is equal to or less than the above upper limit, there is a tendency that a polyamide resin composition having excellent appearance of molded articles and excellent productivity can be obtained.
In addition, the sulfuric acid relative viscosity can be measured by a method based on JIS K 6920.
The sulfuric acid relative viscosity can be controlled by adjusting the pressure during polymerization of (A-2) a polyamide resin other than polyamide 66.

[(A-2) / (A-1)]
The mass ratio (A-2)/(A-1) of (A-2) a polyamide resin other than polyamide 66 to (A-1) polyamide 66 is preferably 5/95 or more and 95/5 or less, and 5/95 or more. 80/20 is more preferable, and 15/85 or more and 70/30 or less is even more preferable. When (A-2)/(A-1) is within the above range, the blow moldability tends to be more excellent.

[Terminal blocking agent]
In the production of (A-1) polyamide 66 and (A-2) polyamide resins other than polyamide 66, a terminal blocker may be further added to adjust the molecular weight when polymerizing the polymerizable monomers. . The terminal blocking agent is not particularly limited, and known ones can be used.

Examples of terminal blocking agents include, but are not limited to, monocarboxylic acids, monoamines, acid anhydrides, monoisocyanates, monoacid halides, monoesters, and monoalcohols. Among them, monocarboxylic acids or monoamines are preferable from the viewpoint of thermal stability. One of these terminal blockers may be used alone, or two or more thereof may be used in combination.

Any monocarboxylic acid may be used as long as it is reactive with an amino group, and examples thereof include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids.
Examples of aliphatic monocarboxylic acids include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid and the like.
Examples of the alicyclic monocarboxylic acid include, but are not limited to, cyclohexanecarboxylic acid.
Examples of aromatic monocarboxylic acids include, but are not limited to, benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid.
These monocarboxylic acids may be used singly or in combination of two or more.

Any monoamine may be used as long as it is reactive with a carboxyl group, and examples thereof include aliphatic monoamines, alicyclic monoamines, and aromatic monoamines.
Examples of aliphatic monoamines include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine. etc.
Examples of the alicyclic monoamine include, but are not limited to, cyclohexylamine, dicyclohexylamine, and the like.
Examples of aromatic monoamines include, but are not limited to, aniline, toluidine, diphenylamine, naphthylamine, and the like.
These monoamines may be used singly or in combination of two or more.

Examples of acid anhydrides include, but are not limited to, phthalic anhydride, maleic anhydride, benzoic anhydride, acetic anhydride, hexahydrophthalic anhydride, and the like.
These acid anhydrides may be used singly or in combination of two or more.

Examples of monoisocyanates include, but are not limited to, phenylisocyanate, tolylisocyanate, dimethylphenylisocyanate, cyclohexylisocyanate, butylisocyanate, naphthylisocyanate, and the like.
These monoisocyanates may be used singly or in combination of two or more.

Examples of monoacid halides include, but are not limited to, benzoic acid, diphenylmethanecarboxylic acid, diphenylsulfonecarboxylic acid, diphenylsulfoxidecarboxylic acid, diphenylsulfidecarboxylic acid, diphenylethercarboxylic acid, benzophenonecarboxylic acid, biphenyl Halogen-substituted monocarboxylic acids such as carboxylic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid and anthracenecarboxylic acid can be mentioned.
These monoacid halides may be used singly or in combination of two or more.

Examples of monoesters include, but are not limited to, glycerin monopalmitate, glycerin monostearate, glycerin monobehenate, glycerin monomontanate, pentaerythritol monopalmitate, pentaerythritol monostearate, Pentaerythritol monobehenate, pentaerythritol monomontanate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monobehenate, sorbitan monomontanate, sorbitan dimontanate, sorbitan trimontanate, sorbitol monopalmitate, sorbitol monostea sorbitol monobehenate, sorbitol tribehenate, sorbitol monomontanate, sorbitol dimontanate and the like.
These monoesters may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of monoalcohols include, but are not limited to, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexa Decanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tricosanol, tetracosanol, hexacosanol, heptakosanol, octacosanol, triacontanol (the above molar alcohols may be linear , may be branched), oleyl alcohol, behenyl alcohol, phenol, cresol (o-, m-, or p-form), biphenol (o-, m-, or p-form), 1-naphthol, 2-naphthol and the like.
These monoalcohols may be used singly or in combination of two or more.

[(A) content of polyamide resin]
In the polyamide resin composition of the present embodiment, the total content of (A-1) polyamide 66 and (A-2) polyamide resins other than polyamide 66, that is, the content of (A) polyamide resin is the polyamide resin composition. 50% by mass or more and 95% by mass or less is preferable, and 60% by mass or more and 95% by mass or less is more preferable with respect to the total mass of. (A) When the content of the polyamide resin is within the above range, there is a tendency that the blow moldability and the strength, heat aging resistance, chemical resistance, specific gravity, etc. of the molded article are excellent.

<(B) Ethylene-maleic acid derivative random copolymer>
(B) Ethylene-maleic acid derivative random copolymers include, but are not limited to, maleated polyolefins that are copolymers of ethylene and maleic anhydride, and functional equivalents thereof. included. Maleic anhydride derivatives from which such functional equivalents are derived include maleic acid and its salts, maleic acid diesters, maleic acid monoesters, itaconic acid, fumaric acid, and fumaric acid monoesters. These maleic anhydride derivatives may be used singly or in combination of two or more.

Maleated polyolefins include E/X/Y terpolymers (where E is ethylene, X is vinyl acetate, and one or more monomers selected from the group consisting of (meth)acrylic acid and its derivatives). ) and Y is a maleic anhydride derivative).
As the structural unit X, a (meth)acrylic acid derivative is preferred. (Meth)acrylic acid derivatives include acids, salts, esters, anhydrides, or other acid derivatives known to those skilled in the chemical arts. As the structural unit X, methyl acrylate or butyl acrylate is also preferred.
As the structural unit Y, maleic acid diester or maleic acid monoester (maleic acid semi-ester) is preferable. Maleic acid diesters or maleic acid monoesters (maleic acid half-esters) include esters of maleic acid and alcohols having an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and the like.
Maleic anhydride derivatives, which are raw materials for maleated polyolefin, are preferably maleic anhydride, maleic acid diesters, or maleic acid half esters, and preferably maleic anhydride or maleic acid half esters.

Maleated polyolefin can be produced by a high-pressure radical method. As the high-pressure radical method, for example, the method described in US Pat. No. 4,351,931 (Reference 1) can be used.

[(B) Content of ethylene-maleic acid derivative random copolymer]
In the polyamide resin composition of the present embodiment, the content of (B) ethylene-maleic acid derivative random copolymer is the total mass of (A-1) polyamide 66 and (A-2) polyamide resins other than polyamide 66: 100 5 parts by mass or more and 30 parts by mass or less is preferable, and 5 parts by mass or more and 20 parts by mass or less is more preferable with respect to 100 parts by mass of the (A) polyamide resin. When the content of the ethylene-maleic acid derivative random copolymer (B) is within the above range, there is a tendency for thickness unevenness, drawdown properties, and appearance to be excellent during blow molding.

<(C) Inorganic filler>
The polyamide resin composition of the present embodiment can further contain (C) an inorganic filler in addition to the above component (A-1), the above component (A-2), and the above component (B).

(C) Inorganic fillers include, but are not limited to, glass fibers, carbon fibers, calcium silicate fibers, potassium titanate fibers, aluminum borate fibers, glass flakes, talc, kaolin, and 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, aluminosilicate sodium silicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, mica, montmorillonite, swelling fluoromica, apatite, etc. mentioned. Among them, from the viewpoint of increasing the strength and rigidity of the resulting molded article, glass fibers having circular and non-circular cross sections, glass flakes, talc (magnesium silicate), mica, kaolin, wollastonite, titanium oxide, calcium phosphate, carbonate Calcium or calcium fluoride are preferred. More preferred are glass fiber, wollastonite, talc, mica, or kaolin, and even more preferred is glass fiber.
These (C) inorganic fillers may be used singly or in combination of two or more.

The glass fibers and carbon fibers have a number average fiber diameter of 3 μm or more and 30 μm or less and a weight average fiber length of 100 μm or more and 750 μm or less, from the viewpoint that excellent mechanical properties can be imparted to 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 preferably 10 or more and 100 or less.

Wollastonite has a number average fiber diameter of 3 μm or more and 30 μm or less, a weight average fiber length of 10 μm or more and 500 μm or less, and an aspect ratio, from the viewpoint of imparting excellent mechanical properties to the polyamide resin composition. is preferably 3 or more and 100 or less.

Talc, mica and kaolin preferably have a number average fiber diameter of 0.1 μm or more and 3 μm or less from the viewpoint of imparting excellent mechanical properties to the polyamide resin composition of the present embodiment.

Here, the number average fiber diameter and weight average fiber length in this specification can be obtained as follows.
That is, the polyamide resin composition is placed in an electric furnace, the contained organic matter is incinerated, and from the residue, for example, 100 or more (C) inorganic fillers are arbitrarily selected, observed with an SEM, and their fiber diameters By measuring and calculating the average value, the number average fiber diameter can be obtained.
In addition, the fiber length is measured using an SEM photograph with a magnification of 1000 times, and a predetermined calculation formula (when the length of n fibers is measured, the weight average fiber length = Σ (I = 1 → n) (the n-th fiber (fiber length of n-th fiber) ² /Σ(I=1→n) (fiber length of n-th fiber)).

[Silane coupling agent]
(C) The inorganic filler may be surface-treated with a silane coupling agent or the like.

Examples of silane coupling agents include, but are not limited to, aminosilanes, mercaptosilanes, epoxysilanes, vinylsilanes, and the like.

Examples of aminosilanes include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and the like.

Mercaptosilanes include, for example, γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

Among them, aminosilanes are preferable as the silane coupling agent from the viewpoint of affinity with the resin.
These silane coupling agents may be used singly or in combination of two or more.

[Sizing agent]
Moreover, when glass fibers are used as the inorganic filler (C), the glass fibers preferably contain a sizing agent. A sizing agent is a component that is applied to the surface of glass fibers.
Examples of the sizing agent include copolymers containing, as structural units, a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic acid anhydride-containing unsaturated vinyl monomer, an epoxy compound, Examples include polycarbodiimide compounds, polyurethane resins, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and salts of these with primary, secondary and tertiary amines.
These sizing agents may be used alone or in combination of two or more.
Among them, from the viewpoint of mechanical strength when formed into a molded article, it comprises a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer. One or more sizing agents selected from the group consisting of copolymers, epoxy compounds, polycarbodiimide compounds, and polyurethane resins contained as units are preferred, and the carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated vinyl monomer are preferably used. A copolymer containing as a structural unit an unsaturated vinyl monomer other than a saturated vinyl monomer is more preferable.

(Copolymer containing, as structural units, a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer)
The carboxylic anhydride, which is a raw material for a copolymer containing, as structural units, a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer. Mono-containing unsaturated vinyl monomers include, but are not limited to, maleic anhydride, itaconic anhydride, and citraconic anhydride. Among them, maleic anhydride is preferred.
On the other hand, the unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer refers to an unsaturated vinyl monomer different from the carboxylic anhydride-containing unsaturated vinyl monomer.
Examples of unsaturated vinyl monomers other than the carboxylic acid anhydride-containing unsaturated vinyl monomer include, but are not limited to, styrene, α-methylstyrene, ethylene, propylene, butadiene, isoprene, Chloroprene, 2,3-dichlorobutadiene, 1,3-pentadiene, cyclooctadiene, methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate and the like. Among them, styrene or butadiene is preferred.
Among these combinations, at least one bundle selected from the group consisting of copolymers of maleic anhydride and butadiene, copolymers of maleic anhydride and ethylene, and copolymers of maleic anhydride and styrene agents are preferred.

Further, in a copolymer containing a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer as structural units, the polyamide resin composition From the viewpoint of improving fluidity, the weight average molecular weight is preferably 2,000 or more, more preferably 2,000 or more and 1,000,000 or less. The weight average molecular weight can be measured by GPC (gel permeation chromatography).

(epoxy compound)
Examples of epoxy compounds include, but are not limited to, aliphatic epoxy compounds, alicyclic epoxy compounds, terpene epoxy compounds, aromatic epoxy compounds, epoxidized soybean oil, and epoxidized linseed oil. be done.

Aliphatic epoxy compounds include, for example, ethylene oxide, propylene oxide, butene oxide, pentene oxide, hexene oxide, heptene oxide, octene oxide, nonene oxide, decene oxide, undecene oxide, dodecene oxide, pentadecene oxide, eiko senoxide and the like.

Examples of alicyclic epoxy compounds include glycidol, epoxypentanol, 1-chloro-3,4-epoxybutane, 1-chloro-2-methyl-3,4-epoxybutane, 1,4-dichloro-2, 3-epoxybutane, cyclopentene oxide, cyclohexene oxide, cycloheptene oxide, cyclooctene oxide, methylcyclohexene oxide, vinylcyclohexene oxide, epoxidized cyclohexene methyl alcohol and the like.

Terpene-based epoxy compounds include, for example, pinene oxide.

Examples of aromatic epoxy compounds include styrene oxide, p-chlorostyrene oxide, m-chlorostyrene oxide and the like.

(Polycarbodiimide compound)
A polycarbodiimide compound is a compound containing one or more carbodiimide groups (-N=C=N-), that is, a compound obtained by condensing carbodiimide compounds.

The degree of condensation of the polycarbodiimide compound is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less. When the degree of condensation is within the range of 1 or more and 20 or less, a better aqueous solution or dispersion can be obtained. Furthermore, when the degree of condensation is within the range of 1 to 10, a better aqueous solution or dispersion can be obtained.

The polycarbodiimide compound is preferably a polycarbodiimide compound partially having polyol segments. By partially having a polyol segment, the polycarbodiimide compound is easily soluble in water, and can be more preferably used as a sizing agent for glass fibers and carbon fibers.

A carbodiimide compound, that is, a compound containing the various carbodiimide groups (-N=C=N-) described above is a diisocyanate compound in the presence of a known carbodiimidation catalyst such as 3-methyl-1-phenyl-3-phospholene-1-oxide. It is obtained by decarboxylation reaction under

As diisocyanate compounds, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and the like can be used. These diisocyanate compounds may be used singly or in combination of two or more.

Specific examples of diisocyanate compounds include, but are not limited to, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene Diisocyanates, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, mixtures of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane- 1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl diisocyanate, 1,3,5-triisopropylbenzene -2,4-diisocyanate and the like.

By carbodiimidating these diisocyanate compounds, a carbodiimide compound having two terminal isocyanate groups is obtained.

Among them, dicyclohexylmethanecarbodiimide is preferable as the carbodiimide compound from the viewpoint of improving reactivity.

Alternatively, a polycarbodiimide compound having one terminal isocyanate group can be obtained by a method of carbodiimidating a monoisocyanate compound in an equimolar amount, or a method of reacting an equimolar amount with a polyalkylene glycol monoalkyl ether to form a urethane bond. be done.

Examples of monoisocyanate compounds include, but are not limited to, hexyl isocyanate, phenyl isocyanate, cyclohexyl isocyanate, and the like.

Examples of polyalkylene glycol monoalkyl ether include, but are not limited to, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, and the like.

(polyurethane resin)
The polyurethane resin may be one that is generally used as a sizing agent, and is not limited to the following. For example, one synthesized from an isocyanate compound and a polyester-based or polyether-based diol. mentioned. Examples of isocyanate compounds include m-xylylene diisocyanate (XDI), 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI), isophorone diisocyanate (IPDI) and the like.

(homopolymer of acrylic acid)
The homopolymer of acrylic acid (polyacrylic acid) preferably has a weight average molecular weight of 1,000 or more and 90,000 or less, more preferably 1,000 or more and 25,000 or less, from the viewpoint of affinity with the resin.

(Copolymer of acrylic acid and other copolymerizable monomers)
As the "other copolymerizable monomer" that forms a copolymer of acrylic acid and other copolymerizable monomer, a monomer having at least one of a hydroxyl group and a carboxyl group is preferred. Specific examples of other copolymerizable monomers include, but are not limited to, acrylic acid, maleic acid, methacrylic acid, vinylacetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, and citraconic acid. , mesaconic acid, etc. (except for acrylic acid alone). These monomers may be used singly or in combination of two or more.
The copolymer of acrylic acid and other copolymerizable monomers preferably has, as a constituent unit, at least one type of ester-based monomer unit among the above-described monomers.

(polymer salt of acrylic acid)
Polymers of acrylic acid (including both homopolymers and copolymers) may be in the form of salts.

Salts of polymers of acrylic acid include, but are not limited to, salts of polymers of acrylic acid with primary, secondary or tertiary amines. Specific examples of amines include triethylamine, triethanolamine, glycine and the like.

The degree of neutralization in the acrylic acid polymer salt is preferably 20% or more and 90% or less from the viewpoint of improving the stability of the mixed solution with other concomitant drugs (silane coupling agent, etc.) and reducing the amine odor. % or more and 60% or less is more preferable.

The weight-average molecular weight of the salt-forming acrylic acid polymer is not particularly limited, but is preferably in the range of 3,000 or more and 50,000 or less. When the weight-average molecular weight is at least the above lower limit, the bundling property of glass fibers and carbon fibers can be further improved. can be improved.

(Processing method with sizing agent)
As a method for treating glass fibers and carbon fibers with various sizing agents, for example, the sizing agents described above are applied to glass fibers and carbon fibers using a known method such as a roller applicator in a known glass fiber or carbon fiber manufacturing process. Examples include a method of continuously reacting by imparting to fibers or carbon fibers and drying the produced fiber strands.

The fiber strands may be used as they are as rovings, or may be further subjected to a cutting process and used as chopped glass strands.

The sizing agent is preferably added (added) at a solid content rate of 0.2% by mass or more and 3% by mass or less with respect to 100% by mass of glass fiber or carbon fiber, and 0.3% by mass or more and 2% by mass or less. It is more preferable to give (add) equivalents. When the amount of the sizing agent to be applied (added) is at least the above lower limit, the sizing of the glass fibers and carbon fibers can be maintained more satisfactorily. On the other hand, when the amount of the sizing agent to be applied (added) is equal to or less than the above upper limit, the thermal stability of the molded article can be further improved.

Drying of the strands may be performed after the cutting step, or the cutting step may be performed after drying the strands.

[(C) Inorganic filler content]
In the polyamide resin composition of the present embodiment, the content of the inorganic filler (C) is preferably 0% by mass or more and 50% by mass or less, and 0% by mass or more and 40% by mass or less, relative to the total mass of the polyamide resin composition. is more preferable, and 0% by mass or more and 30% by mass or less is even more preferable.
(C) When the content of the inorganic filler is within the above range, the blow moldability of the polyamide resin composition tends to be more excellent.

<(D) Alkali metal salt>
The polyamide resin composition of the present embodiment may further contain (D) an alkali metal salt in addition to the components (A-1), (A-2), and (B). The polyamide resin composition of the present embodiment contains (D) an alkali metal salt, so that the alkali metal salt can form a dense structure on the surface of the molded article made of the polyamide resin composition, and heat aging resistance And a molded article having excellent acid resistance can be obtained.

Examples of alkali metal salts include alkali metal carbonates, alkali metal hydrogencarbonates, alkali metal hydroxides, and the like.

Specific examples of alkali metal carbonates include sodium carbonate, potassium carbonate, and the like. These carbonates may be used individually by 1 type, and may be used in combination of 2 or more type.

Alkali metal hydrogen carbonates include, but are not limited to, sodium hydrogen carbonate, potassium hydrogen carbonate, and the like. These hydrogen carbonates may be used alone or in combination of two or more.

Alkaline hydroxides include, but are not limited to, sodium hydroxide, potassium hydroxide, and the like. Alkali metal hydroxides may be used alone or in combination of two or more.

Among them, (D) the alkali metal salt is preferably sodium carbonate, potassium carbonate, sodium hydrogencarbonate or potassium hydrogencarbonate, more preferably sodium carbonate or sodium hydrogencarbonate, from the viewpoint of heat aging resistance.

In the polyamide resin composition of the present embodiment, the (D) alkali metal salt has a particle diameter of 1 μm or more in the (D) alkali metal salt. The content of the particles of the (D) alkali metal salt is 20% by mass. The following is preferable, 15% by mass or less is more preferable, 10% by mass or less is even more preferable, and 5% by mass or less is particularly preferable. When the content of the (D) alkali metal salt particles having a particle diameter of 1 μm or more is equal to or less than the above upper limit value in the (D) alkali metal salt, the heat aging resistance of the resulting molded article tends to be more excellent. .

Here, the particle size of the (D) alkali metal salt is the particle size of the (D) alkali metal salt present in the polyamide resin composition of the present embodiment. The particle size of the (D) alkali metal salt in the polyamide resin composition can be measured, for example, by dissolving the polyamide resin composition in hexafluoroisopropanol (HFIP) and using a laser diffraction particle size distribution device. .

As described above, in order to suppress the content of the (D) alkali metal salt particles having a particle size of 1 μm or more in the (D) alkali metal salt to the above upper limit value or less, it is necessary to keep the water content low (D ) alkali metal salt and (A) polyamide resin ((A-1) polyamide resin other than polyamide 66 and (A-2) polyamide resin) are effectively mixed. For example, there is a method of melt-kneading (D) an alkali metal salt with (A) a polyamide resin using an extruder.

On the other hand, if the (D) alkali metal salt is included in the polycondensation step of the (A) polyamide resin, the diameter of the (D) alkali metal salt may increase. That is, (A) the polyamide resin polymerization process is completed, (A) the polyamide resin is taken out, and (A) the polyamide resin and (D) the alkali metal salt are mixed at the stage of melt kneading, which is the process for producing the polyamide resin composition. preferably.

(D) Alkali metal salt may be added to (A) polyamide at any timing of addition during polymerization or during melt-kneading.

(D) From the viewpoint of the dispersibility of the alkali metal salt, and from the viewpoint of suppressing the content of the (D) alkali metal salt particles having a particle size of 1 μm or more as described above to the above upper limit or less, during melt kneading addition is preferred.

[(D) content of alkali metal salt]
In the polyamide resin composition of the present embodiment, the content of (D) the alkali metal salt is 100 parts by mass of the total mass of polyamide resins other than (A-1) polyamide 66 and (A-2) polyamide 66, that is, (A ) 0.01 parts by mass or more and 2 parts by mass or less is preferable, and 0.2 parts by mass or more and 0.6 parts by mass or less is more preferable with respect to 100 parts by mass of the polyamide resin.
When the content of the (D) alkali metal salt is within the above range, the heat aging resistance and appearance of the molded product are improved.

<(E) Neutralizing agent>
The polyamide resin composition of the present embodiment may further contain (E) a neutralizer in addition to the above components (A-1), (A-2) and (B). When the polyamide resin composition of the present embodiment contains (D) an alkali metal salt, it further contains (E) a neutralizer in order to neutralize the pH since the polyamide resin composition becomes alkaline. is preferred.

(E) The neutralizing agent is not particularly limited as long as it is an acidic compound, and examples thereof include organic acids. Examples of organic acids include, but are not limited to, compounds having a carboxy group, a sulfo group, a hydroxy group, a thiol group, and an enol group. These organic acids may be used individually by 1 type, and may use 2 or more types together.

[Compound having a carboxy group]
Compounds having a carboxy group include, but are not limited to, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid. , hexadecanoic acid, heptadecanoic acid, octadecanoic acid, benzoic acid, oxalic acid, cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, 1,3,5-tetrabenzenetetracarboxylic acid, adipic acid, dodecanedioic acid, citric acid, tartaric acid, Ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid-disodium salt, gluconic acid and the like can be mentioned. Among them, compounds having a carboxy group include cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, 1,3,5-tetrabenzenetetracarboxylic acid, adipic acid, dodecanedioic acid, citric acid, tartaric acid, ethylenediaminetetraacetic acid, and ethylenediaminetetraacetic acid. A compound having two or more carboxy groups in one molecule, such as acetic acid disodium salt, is preferred. These carboxy group-containing compounds may be used alone or in combination of two or more.

[Compound having a sulfo group]
Compounds having a sulfo group include, but are not limited to, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, fluorosulfonic acid, and derivatives thereof. These compounds having a sulfo group may be used singly or in combination of two or more.

[Compound having a hydroxy group]
Compounds having a hydroxy group include, but are not limited to, cyclohexanol, decanol, decanediol, dodecanol, dodecanediol, pentaerythritol, dipentaerythritol, tripentaerythritol, di-trimethylolpropane, D -mannitol, D-sorbitol, xylitol, phenol, and derivatives thereof. These hydroxy group-containing compounds may be used alone or in combination of two or more.

Among them, (E) the neutralizing agent is preferably a compound having a carboxy group.

[alkali value/oxidation value]
In the polyamide resin composition of the present embodiment, the (D) alkali contained in 100 parts by mass of the (A) polyamide resin relative to the acid value of the (E) neutralizing agent contained in 100 parts by mass of the polyamide resin (A) The alkali value ratio (X) of the metal salt preferably satisfies the following formula.

0<X≦5

In the above formula, 0<X≦3 is more preferred, 0<X≦2 is even more preferred, and 0<X≦1 is particularly preferred.

The acid value of the (E) neutralizer contained in 100 parts by mass of the (A) polyamide resin is defined based on JIS K0070. That is, the "acid value" is mg of potassium hydroxide required to neutralize free fatty acid, resin acid, etc. contained in 1 g of sample.

The alkali value of the (D) alkali metal salt contained in 100 parts by mass of the (A) polyamide resin is defined based on JIS K0070. That is, the "alkali value" is mg of potassium hydroxide required to neutralize acetic acid bound to hydroxyl groups when 1 g of sample is acetylated.

In the above, "contained in 100 parts by mass of (A) polyamide resin" means that (A) polyamide resin in the polyamide resin composition of the present embodiment is 100 parts by mass, and in such a case Considering the content of (D) the alkali metal salt and the content of (E) the neutralizing agent, the above formula is calculated.

Furthermore, in the polyamide resin composition of the present embodiment, the acid value of the (E) neutralizing agent contained in 100 parts by mass of the (A) polyamide resin, and the acid value of the carboxy group terminal of the (A) polyamide resin The ratio (Y) of the alkali value of the (D) alkali metal salt contained in 100 parts by mass of the (A) polyamide resin to the sum preferably satisfies the following formula:

0<Y≦3

In the above formula, 0<Y≦2 is more preferable, 0<Y≦1.5 is more preferable, and 0<Y≦1.2 is particularly preferable.

In the above formula, "(A) contained in 100 parts by mass of the polyamide resin" means that the (A) polyamide resin in the polyamide resin composition of the present embodiment is 100 parts by mass. The above formula is calculated in consideration of (A) the carboxy group terminal concentration of the polyamide resin, (D) the content of the alkali metal salt, and (E) the content of the neutralizing agent.

Regarding (E) the neutralizing agent and (A) the carboxylic acid in the polyamide resin, the relationship between the neutralizing agent and the terminal blocking agent is supplemented below.
(A) Carboxylic acid used as a raw material monomer for polyamide resin or a terminal blocking agent is incorporated into the polymer for that purpose. Specifically, it is covalently bound in the polymer chain.
On the other hand, for that purpose, the organic acid component having a carboxylic acid functional group that is not covalently bonded to the polymer is referred to herein as (E) the neutralizing agent. (A) a carboxylic acid used as a raw material monomer or terminal blocker for a polyamide and (E) a carboxylic acid used as a neutralizing agent are the same components, (A) a raw material monomer for a polyamide or a terminal blocker Carboxylic acids used as refer to carboxylic acids that are covalently attached in the polymer chain, and carboxylic acids used as (E) neutralizing agents refer to carboxylic acids that are not covalently attached to the polymer.

(A) Those skilled in the art generally recognize that when a carboxylic acid is used as a raw material monomer or a terminal blocking agent for a polyamide resin, the carboxylic acid is covalently bonded in the polymer chain. It is an intentional operation to contain carboxylic acid in the polyamide in a state where it is not covalently bonded in the polymer chain in an amount exceeding a trace amount as an impurity, and it is necessary to devise the composition and manufacturing method for that purpose. is the general recognition of those skilled in the art. That is, even if a carboxylic acid is used as a raw material in a normal polyamide resin composition, the (E) carboxylic acid as a neutralizing agent intended in the present embodiment is unintentionally contained. I don't think so.

The above description relates to (A) an organic acid that can be used as a neutralizing agent or a terminal blocker in a polyamide resin, specifically an organic acid having 1 to 3 carboxylic acid functional groups in one molecule. On the other hand, an organic acid molecule having 4 or more carboxylic acid functional groups in one molecule exhibits the effects of the present embodiment even if some of the carboxylic acid functional groups are covalently bonded to the polyamide. That is, an organic acid having 1 or more and 3 or less carboxylic acid functional groups in one molecule cannot sufficiently exhibit the effects of the present embodiment if some of the carboxylic acid functional groups are covalently bonded to the polyamide. An organic acid having 4 or more carboxylic acid functional groups in its molecule exhibits the effects of the present embodiment even if some of the carboxylic acid functional groups are covalently bonded to the polyamide. For the above reasons, the present inventors have found that by having 4 or more carboxylic acid functional groups in one molecule, even if some of them are covalently bonded to the polyamide, the remaining non-covalently bonded carboxylic acid functional groups contributes to the effect of this embodiment.

Confirmation of the covalent bond between the above-described organic acid and the polymer of the polyamide resin (A) is not limited to the following, but for example, using known methods such as Soxhlet extraction, nuclear magnetic resonance (NMR), IR, etc. It can be carried out.

(E) The neutralizing agent may be added to the (A) polyamide resin at any time during polymerization or during melt-kneading, but (E) the neutralizing agent is added during melt-kneading. preferably.

[(E) Neutralizing agent content]
In the polyamide resin composition of the present embodiment, the content of (E) the neutralizing agent may be an amount that can sufficiently neutralize the (D) alkali metal salt, and depending on the content of the (D) alkali metal salt can be adjusted accordingly. For example, when the content of (D) the alkali metal salt is within the above range, the total mass of (A-1) polyamide 66 and (A-2) polyamide resin other than polyamide 66 is 100 parts by mass, that is, (A) polyamide 0.01 to 2 parts by mass is preferable with respect to 100 parts by mass of resin, and 0.3 to 1 part by mass is more preferable.
When the content of (E) the neutralizing agent is within the above range, the (D) alkali metal salt contained in the polyamide resin composition can be more sufficiently neutralized.

<(F) elemental iron>
The polyamide resin composition of the present embodiment can contain (F) elemental iron in addition to the above component (A-1), the above component (A-2), and the above component (B). By containing (F) elemental iron, the polyamide resin composition of the present embodiment can form a dense crosslinked structure between the polyamide present especially on the surface of the obtained molded article and the elemental iron, and is heat resistant. It is possible to obtain molded articles that are more excellent in aging resistance and acid resistance.

(F) Elemental iron is preferably small-particle elemental iron having a weight-average particle size of 450 μm or less.
The upper limit of the weight average particle size of (F) elemental iron is preferably 450 μm, more preferably 250 μm, even more preferably 200 μm, particularly preferably 100 μm, and most preferably 50 μm. On the other hand, the lower limit of the weight average particle size of (F) elemental iron is not particularly limited, but may be 1 μm, 5 μm, or 10 μm. That is, the weight average particle size of (F) elemental iron is preferably 1 μm or more and 450 μm or less, more preferably 1 μm or more and 250 μm or less, even more preferably 5 μm or more and 200 μm or less, particularly preferably 5 μm or more and 100 μm or less, and most preferably 10 μm or more and 50 μm or less. preferable.
Weight average particle size is determined according to ASTM Standard D1921-89, Method A, as Dm.

The upper limit of the particle size of at least 50% by weight of the elemental iron particles, taken as the largest dimension, is preferably 450 μm, more preferably 250 μm, even more preferably 200 μm, particularly preferably 100 μm and most preferably 50 μm. More preferably, at least 75% by mass, more preferably 90% by mass of the elemental iron particles have a particle size equal to or less than the above upper limit.

(F) Elemental iron may be added to the masterbatch. The polymer used in the masterbatch is not limited to the (A) polyamide resin, and may be another polymer, preferably having a melting point lower than that of the (A) polyamide resin.

[(F) Content of elemental iron]
(F) The content of elemental iron is 0 for the total mass of 100 parts by mass of (A-1) polyamide 66 and (A-2) polyamide resin other than polyamide 66, that is, 100 parts by mass of (A) polyamide resin 05 parts by mass or more and 10 parts by mass or less is preferable, and 0.1 parts by mass or more and 5 parts by mass or less is more preferable.
(F) When the content of elemental iron is at least the above lower limit, the heat aging resistance is further improved.

<(G) Copper halide>
The polyamide resin composition of the present embodiment can contain (G) a copper halide in addition to the above component (A-1), the above component (A-2), and the above component (B). The polyamide resin composition of the present embodiment tends to further improve heat aging resistance by containing (G) a copper halide.

Examples of (G) copper halide include, but are not limited to, copper iodide, cuprous bromide, cupric bromide, and cuprous chloride. These (G) copper halides may be used alone or in combination of two or more.

[(G) Copper halide content]
The content of (G) copper halide is the total mass of polyamide resins other than (A-1) polyamide 66 and (A-2) polyamide 66 when (G) copper halide is selected as a component 100 parts by mass, that is, with respect to 100 parts by mass of (A) polyamide resin, the content of (G) copper halide in terms of metal elements is preferably 0.001 parts by mass or more and 0.05 parts by mass or less, and 0 0.003 parts by mass or more and 0.05 parts by mass or less is more preferable, and 0.005 parts by mass or more and 0.03 parts by mass or less is even more preferable. (G) When the content of the copper halide is within the above range, the heat aging resistance can be further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

<(H) One or more halides selected from the group consisting of alkali metal halides and alkaline earth metal halides>
The polyamide resin composition of the present embodiment contains (H) an alkali metal halide and an alkaline earth metal in addition to the above component (A-1), the above component (A-2), and the above component (B). It can contain one or more halides selected from the group consisting of halides (hereinafter sometimes simply referred to as "halides"). The polyamide resin composition of the present embodiment tends to further improve heat aging resistance by containing (H) a halide.

Examples of (H) halides include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and the like. Among them, potassium iodide and/or potassium bromide are preferred, and potassium iodide is more preferred, from the viewpoint of improving heat resistance and suppressing metal corrosion. These (H) halides may be used alone or in combination of two or more.

Each of the (G) copper halide and (H) halide may be used alone or in combination of two or more.
Among them, from the viewpoint of further improving heat resistance, it is preferable to use (G) copper halide and (H) halide in combination.

The molar ratio of the halogen element to the metal element (halogen element/metal element) in the mixture of (G) copper halide and (H) halide is preferably 2 or more and 50 or less, more preferably 2 or more and 40 or less, and 5 or more and 30 More preferred are: When the halogen element/metal element ratio is within the above range, the heat aging resistance can be further improved.

[(H) halide content]
The content of (H) halide is 100 parts by mass of the total mass of polyamide resins other than (A-1) polyamide 66 and (A-2) polyamide resin other than polyamide 66, that is, (A) per 100 parts by mass of polyamide resin, 0 05 parts by mass or more and 5 parts by mass or less is preferable, and 0.2 parts by mass or more and 2 parts by mass or less is more preferable. When the content of (H) halide is within the above range, the heat aging resistance is further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

<(I) Other components>
The polyamide resin composition of the present embodiment, in addition to the above component (A-1), the above component (A-2), and the above component (B), to the extent that the effects of the present embodiment are not impaired, if necessary In addition, (I) other components can be further contained.

(I) Other components include, but are not limited to, ultraviolet absorbers, photodegradation inhibitors, plasticizers, lubricants, release agents, nucleating agents, flame retardants, colorants, staining agents, pigments, other thermoplastic resins, and the like.

Since the properties of the above and other components differ greatly, there are various suitable contents of each component that do not impair the effects of the present embodiment. A person skilled in the art can easily set a suitable content for each of the other components described above.

<Method for producing polyamide resin composition>
The polyamide resin composition of the present embodiment includes (A) a polyamide resin ((A-1) a polyamide resin other than polyamide 66 and (A-2) polyamide 66) and (B) an ethylene-maleic acid derivative random copolymer. and, if necessary, the above components (C) to (I).

As a method for mixing the above components (A) to (B) and, if necessary, the above components (C) to (I), for example, the following (1) or (2) methods and the like.
(1) The above components (A) to (B) and, if necessary, the above components (C) to (I) are mixed using a Henschel mixer or the like, supplied to a melt kneader and kneaded. how to.
(2) In a single-screw or twin-screw extruder, each of the above components (A) to (C) and, if necessary, the above components (D) to (I) are mixed in advance using a Henschel mixer or the like. to prepare a mixture containing each component (A) to (B) and, if necessary, the above components (D) to (I), and after kneading the mixture by supplying it to a melt kneader, optionally A method of blending the (C) component from the side feeder.

As for the method of supplying the components constituting the polyamide resin composition to the melt kneader, all the components may be supplied to the same supply port at once, or the components may be supplied from different supply ports.

The temperature of melt-kneading is preferably (A-1) a temperature higher than the melting point of polyamide 66 by about 1° C. or higher and 100° C. or lower, and (A-1) a temperature higher than the melting point of polyamide 66 by about 10° C. or higher and 50° C. or lower is more preferable. .

The shear rate in the kneader is preferably about 100 sec -1 or more. Also, the average residence time during kneading is preferably about 0.5 minutes or more and 5 minutes or less.

As a device for melt-kneading, any known device may be used, and for example, a single-screw or twin-screw extruder, a Banbury mixer, a melt-kneader (mixing roll, etc.), etc. are preferably used.

The blending amount of each component when producing the polyamide resin composition of the present embodiment is the same as the content of each component in the polyamide resin composition described above.

In the polyamide resin composition of the present embodiment, when containing the above components (D) to (F), (A) the polyamide resin and (B) ethylene-maleic acid derivative random by a single-screw or multi-screw extruder A method of kneading (D) an alkali metal salt, (E) a neutralizing agent and (F) elemental iron in a molten state of a copolymer, that is, (D) an alkali metal salt, (E) a neutralizing agent and ( F) A method of adding elemental iron to (A) a polyamide resin and (B) an ethylene-maleic acid derivative random copolymer by melt-kneading can be preferably used.

Further, an aqueous solution of (D) an alkali metal salt and (F) an elemental iron, (A) polyamide resin pellets, and (B) an ethylene-maleic acid derivative random copolymer are well stirred and mixed in advance to form a mixture. After obtaining, the polyamide resin pellets obtained by drying the water content of the mixture and (E) the neutralizing agent are fed from the feed port of the extruder and melt-kneaded. can.

Furthermore, it is preferable to have a step of masterbatching (D) an alkali metal salt, (E) a neutralizing agent and (F) elemental iron and adding them.
That is, (D) an alkali metal salt, (E) a neutralizing agent, and (F) an alkali metal salt at a concentration higher than that of elemental iron to be added to the final polyamide composition, (E) After melt-kneading the admixture and (F) elemental iron with (A) polyamide resin and (B) ethylene-maleic acid derivative random copolymer and pelletizing, the pellets and, if necessary, the above (C) and From the viewpoint of heat aging resistance, it is preferable to melt-knead the components (G) to (I) to finally produce the desired polyamide resin composition.

<Characteristics of Polyamide Resin Composition>
[tan δ(1)/tan δ(100)]
In the polyamide resin composition of the present embodiment, (A-1) Polyamide 66 and (A-2) Among the polyamide resins other than polyamide 66, the melting point of the polyamide resin having the highest melting point + 10 ° C. Measured with a rotary rheometer It is preferable that the tan δ obtained by the formula satisfies the following formula.

(In the formula, tan δ (1) represents tan δ when measured at an angular velocity of 1 rad/sec, and tan δ (100) represents tan δ when measured at an angular velocity of 100 rad/sec.)

In the above formula, tan δ(1)/tan δ(100) is preferably less than 0.75, more preferably 0.70 or less, even more preferably 0.65 or less. When tan δ(1)/tan δ(100) is within the above range, the blow moldability can be further improved.

The tan δ measurement in a rotational rheometer can be measured, for example, by a deformation-controlled rheometer (rotational rheometer) manufactured by TA-Instruments (ARES). Specifically, it can be measured using the following method.
First, before measurement, a measurement sample formed by molding the polyamide resin composition of the present embodiment is vacuum-dried at 80° C. for 8 hours. The sample is then placed on the preheated lower plate of the rheometer and the oven is closed. The upper plate is then moved downwards until a measuring gap of 0.5 mm is reached. From here a 2 minute preheat is applied and the supernatant sample between the two plates is removed with a spatula before starting the measurement. Measurement conditions can be, for example, the conditions shown below.

(Measurement condition)
Measurement sample: Cone plate φ25mm
Measurement gap: 0.5mm
Melting time: 2 minutes Distortion: 10%
Temperature: (A) Melting point of polyamide resin with the highest melting point among polyamide resins + 10 ° C
Angular velocity: 200rad/s to 0.5rad/s

From the above measurement results, tan δ when the angular velocity is 1 rad/s is tan δ (1), tan δ when the angular velocity is 100 rad/s is tan δ (100), and the ratio of tan (1) to tan (100) is tan (1 )/tan(100) can be calculated.

[Number average molecular weight (Mn)]
The number average molecular weight (Mn) of the polyamide resin composition of the present embodiment is preferably 10,000 or more, more preferably 12,000 or more, and even more preferably 15,000 or more, from the viewpoint of mechanical properties and heat resistance.
The number average molecular weight can be determined using GPC using a sample obtained by dissolving the polyamide resin composition in HFIP, which is a solvent, and is substantially the (A) polyamide resin in the polyamide resin composition, or (A) It corresponds to the number average molecular weight of the (A) polyamide resin including the components covalently bonded to the polyamide resin.

≪Manufacturing method of molded product≫
The method for producing a molded article of the present embodiment (hereinafter sometimes simply referred to as "the production method of the present embodiment") is a method of molding the polyamide resin composition by blow molding.

In the manufacturing method of the present embodiment, since molding is performed by blow molding, even a molded product with a complicated shape can be obtained by one-time molding without joining parts. In addition, by using the above polyamide resin composition, a molded article having good blow moldability during production, specifically good thickness uniformity and surface appearance, and excellent heat aging resistance and chemical resistance can be obtained.

Specifically, as the manufacturing method of the present embodiment, for example, a blow molding machine equipped with an extruder is used to produce a cylindrical container called a parison with the extruder, and then the parison is inserted into a mold. By inflating, a molded product is obtained.

In the case of injection molding, when the plastic is melted and pushed in, a very high pressure is applied to the mold and the clamping part, but in the case of blow molding, the pressure on the mold is very small, only a few atmospheres, because it only expands. Become.

Although there is no particular limitation on the blow molding machine used for manufacturing molded products, for example, S.M. T. SOFFIAGGIO TECNICA S.A. r. 1 (ASPI150.3) 3D suction blow molding machine.

The molded article obtained by the production method of the present embodiment preferably has a hollow shape, and is not limited to the following, for example, for automobiles, machinery industry, electricity and electronics, industrial materials It can be suitably used as a material part for various uses such as industrial materials, daily use and household goods. In particular, it is suitably used as a material part for automobiles. Furthermore, the molded article obtained by the production method of the present embodiment is excellent in heat aging resistance and chemical resistance, and therefore is suitably used for turbo ducts and battery cooling pipes among automotive material parts.

EXAMPLES The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

Each component of the polyamide compositions used in Examples and Comparative Examples will be described below.

<Constituent>
[(A) polyamide resin]
A-1: Polyamide 66 (PA66) (manufactured by Asahi Kasei Corporation, model number: Leona 1300, melting point 262° C., sulfuric acid relative viscosity 2.6, amino group terminal concentration 46 μmol / g, carboxy group terminal concentration 78 μmol / g)
A-2-1: Polyamide 6 (PA6) (manufactured by Ube Industries, model number: SF1013A, melting point 220° C., sulfuric acid relative viscosity 2.4, amino group terminal concentration 41 μmol / g, carboxy group terminal concentration 78 μmol / g)
A-2-2: Polyamide 612 (PA612) (manufactured by Asahi Kasei Corporation, model number: Leona 4100, melting point 215 ° C., sulfuric acid relative viscosity 2.2, amino group terminal concentration 72 μmol / g, carboxy group terminal concentration 62 μmol / g)

The melting point of each polyamide resin was measured according to JIS-K7121 using a Diamond DSC manufactured by PERKIN-ELMER.

The 98% sulfuric acid relative viscosity of each polyamide resin was measured according to JIS-K6920.

The terminal amino group concentration of each polyamide resin was measured by neutralization titration as follows.
First, 3.0 g of the obtained polyamide was dissolved in 100 mL of 90% by mass phenol aqueous solution. Then, using the obtained solution, titration was performed with 0.025N hydrochloric acid to determine the terminal amino group concentration (μmol/g). The endpoint was determined from the pH meter reading.

The terminal carboxy group concentration of each polyamide resin was measured by neutralization titration as follows.
First, 4.0 g of the obtained polyamide was dissolved in 50 mL of benzyl alcohol. Then, using the obtained solution, titration was performed with 0.1N NaOH to determine the terminal carboxyl group concentration (μmol/g). The endpoint was determined from the color change of the phenolphthalein indicator.

[(B) Ethylene-maleic acid derivative random copolymer]
B-1: Ethylene-ethyl hydrogen maleate random copolymer (content of ethyl hydrogen maleate units: 8% by mass relative to the mass of all constituent units of the copolymer)

[(B') other copolymers]
B'-1: Styrene-maleic anhydride copolymer (manufactured by Kawase Chemical Co., Ltd., trade name "SMA3000")
B'-2: ethylene-maleic anhydride copolymer (manufactured by Verellus, trade name "ZeMacE400")
B'-3: Maleic anhydride-grafted ethylene-octene copolymer (manufactured by DUPONT, trade name "FusabondN493D")

[(C) filler]
C-1: Glass fiber (GF) (manufactured by Nippon Electric Glass, trade name “ECS03T275H” average fiber diameter 10 μmφ, cut length 3 mm)

[(D) Alkali metal compound]
D-1: Sodium carbonate (manufactured by Tokuyama Corporation, trade name "Soda Ash Light")

[(E) Neutralizing agent]
E-1: 1,4-cyclohexanedicarboxylic acid (CHDA) (manufactured by Shin Nippon Rika Co., Ltd., trade name “Likacid CHDA”)

[(F) elemental iron]
F-1: Masterbatch containing elemental iron particles (manufactured by ALBIS, trade name “SHELEFPLUS2 3302DP”)

[(G) Copper Halide Compound]
G-1: Copper iodide (manufactured by Wako Pure Chemical Industries, Ltd.)

[(H) one or more halides randomly selected from alkali metal halides and alkaline earth metal halides]
H-1: potassium iodide (manufactured by Wako Pure Chemical Industries, Ltd.)

[ ^Synthesis example] Synthesis of ethylene-ethyl hydrogen maleate random copolymer Each component was dissolved in benzene to form acetate to prepare a benzene solution. The prepared benzene solution and ethylene at a mass ratio of 1:1 were continuously fed into a 2 L autoclave equipped with a stirrer for stirring at 300 rpm until the pressure reached 1200 atm. After that, the autoclave was heated to 230° C. with a jacket heater. The resulting polymer solution was transferred through a pressure reducing valve to a separate vessel to rapidly evaporate all reagents except the polymer. The polymer was discharged from the lower nozzle in the form of a strand, water-cooled and cut to obtain pellets of an ethylene-ethyl hydrogen maleate random copolymer. The content of ethyl hydrogen maleate was 8% by mass with respect to the mass of all structural units of the resulting ethylene-ethyl hydrogen maleate random copolymer. The content of ethyl hydrogen maleate with respect to the mass of all structural units of the ethylene-ethyl hydrogen maleate random copolymer was measured by H-NMR. Also, the melt index under a load of 2.16 kg at 210° C. was 25 g/10 min.

<Physical properties and evaluation methods of molded products>
[Manufacturing of molded products]
The polyamide composition pellets obtained in Examples and Comparative Examples were dried in a nitrogen stream to reduce the water content in the polyamide composition to 500 ppm or less. Next, using an injection molding machine (PS-40E, manufactured by Nissei Plastics Co., Ltd.), pellets of each polyamide composition with adjusted moisture content are subjected to multi-purpose test pieces (A type, dumbbell-shaped tensile test) in accordance with ISO 3167. pieces) were molded as moldings. The dimensions of the multi-purpose test piece were as follows: total length ≧170 mm, distance between tabs 109.3±3.2 mm, length of parallel portion 80±2 mm, radius of shoulder 24±1 mm, width of end 20±0.2 mm. 2 mm, the width of the central parallel portion is 10±0.2 mm, and the thickness is 4±0.2 mm. Specific injection molding conditions were as follows: injection and holding pressure time: 25 seconds, cooling time: 15 seconds, mold temperature: 80°C, and cylinder temperature: 290°C.

[Physical property 1] tan δ (1)/tan δ (100)
Using a circular flat plate of 25 mm×25 mm×2 mm cut out from the multipurpose test piece, tan δ was measured under the following conditions.

(Measurement condition)
Test piece: Cone plate φ25mm
Measurement gap: 0.5mm
Melting time: 2 minutes Distortion: 10%
Temperature: Melting point of polyamide 66 262°C + 10°C
Angular velocity: 200rad/s to 0.5rad/s

The tan δ at an angular velocity of 1 rad/s was tan δ(1), and the tan δ at an angular velocity of 100 rad/s was tan δ(100), and {tan(1)/tan(100)} was calculated.

[Evaluation 1] Blow Moldability The polyamide resin compositions obtained in Examples and Comparative Examples were dried at 80° C. for 8 hours, and then molded into a pipe-shaped mold of 800 mm×60 mm×60 mm and a blow molding machine (ST. ASPI150.3) manufactured by SOFFIAGGIO TECNICA S.r.l) was used to evaluate blow moldability for the following evaluation items.

1. Parison sag (axial difference in wall thickness over the entire length of the pipe)
Measure the difference between the thickness of the molded product at a position of 100 mm in the longitudinal direction from the end of the molded product and the thickness of the molded product at a position of 700 mm in the longitudinal direction from the end of the molded product, and use the following evaluation criteria was evaluated according to

(Evaluation criteria)
4: Thickness difference is 0.5 mm or less 3: Thickness difference is more than 0.5 mm and 2.0 mm or less 2: Thickness difference is more than 2.0 mm

2. Swelling behavior at the die exit Measure the parison diameter (unit: mm) at a position 30 mm in the extrusion direction from the die exit, and calculate the ratio of the parison diameter to the die diameter at that position (parison diameter/die diameter). Then, it was evaluated according to the following evaluation criteria.

(Evaluation criteria)
◎: parison diameter / die diameter is 1.1 or more ○: parison diameter / die diameter is 1.0 or more and less than 1.1 ×: parison diameter / die diameter is less than 1.0

3. Surface smoothness of the inside and outside of the molded product (pipe) Evaluation of the surface smoothness of the molded product (pipe) is carried out by measuring the surface of the molded product with a surface roughness meter (Surftest model SJ-400, manufactured by Mitutoyo Co., Ltd.). was used to measure five different points with a measurement length of 1 cm, and the maximum surface roughness (Rmax) of them was measured and evaluated according to the following evaluation criteria.

(Evaluation criteria)
◎: Rmax is 500 or less ○: Rmax is more than 500 and 750 or less ×: Rmax is more than 750

[Evaluation 3] Heat Aging Resistance Using each multi-purpose test piece (Type A), a tensile test was performed at a tensile speed of 5 mm/min according to ISO527 to measure the initial tensile strength (MPa) (S0). Next, each multi-purpose test piece (Type A) was placed in an oven conforming to ISO188 and heated under two conditions of 150° C. and 180° C. for 2000 hours to conduct a heat aging test. After 2000 hours, each multi-purpose specimen (Type A) was removed from the oven and allowed to cool at 23°C for 24 hours. Next, each multi-purpose test piece (A type) after the heat aging test was subjected to a tensile test (same conditions as the tensile test before the heat aging test) in accordance with ISO 527 at a tensile speed of 5 mm / min. Tensile strength (MPa) was measured (S1). Then, the tensile strength retention (%) was calculated using the formula shown below.

Tensile strength retention (%) = S1/S0 x 100

[Evaluation 4] Chemical resistance
The polyamide resin composition pellets obtained in Examples and Comparative Examples are injected using an injection molding machine (PS-40E, manufactured by Nissei Plastics Co., Ltd.), injection + holding pressure time 10 seconds, cooling time 15 seconds, mold temperature Under conditions of 80°C and a molten resin temperature of 290°C, it was molded into a flat plate shaped piece of 60 mm x 60 mm x 3 mm. Next, from the flat plate in the direction perpendicular to the flow (the direction perpendicular to the axis in the direction of the end of the flow from the gate of the molded product), cut into a small tensile test piece type 4 shape conforming to ISO8256. got Using the obtained test piece, a tensile test was performed at a distance between chucks of 30 mm and a tensile speed of 1 mm/min to measure the initial tensile strength (MPa). Then, using an autoclave, the test piece was immersed in a chemical agent [pure water/long-life coolant liquid (LLC liquid, G48 manufactured by BASF)=50/50 (volume ratio)] at 130° C. for 1000 hours. The test piece after immersion in the chemical was subjected to a tensile test under the same conditions as the tensile test before immersion in the chemical, and the tensile strength (MPa) after immersion in the chemical was measured. The tensile strength retention after immersion for 1000 hours was calculated according to the formula shown below.

Tensile strength retention after 1000 hours of chemical immersion = tensile strength after chemical immersion/initial tensile strength x 100

<Production of Polyamide Resin Composition>
[Example 1]
(Production of polyamide resin composition Pa1)
Using a TEM 35 mm twin-screw extruder (set temperature: 280° C., screw rotation speed 300 rpm) manufactured by Toshiba Machine Co., Ltd., (A) polyamide resin (A-1: PA66 and A-2-1: PA6), (B) ethylene-maleic acid derivative random copolymer B-1, (G) copper halide G-1, and (H) alkali metal halide H-1 in advance. A blend of Further, (C) the filler C-1 was supplied from the side feed port on the downstream side of the extruder (in a state in which the resin supplied from the top feed port was sufficiently melted). Next, the melt-kneaded product extruded from the die head was cooled in a strand form and pelletized to obtain pellets of the polyamide resin composition Pa1. The kind and content of each component were as shown in Table 1.

[Examples 2 to 13 and Comparative Examples 1 to 8]
(Production of Polyamide Resin Compositions Pa2 to Pa13 and Pb1 to Pb8)
Polyamide resin compositions P-a2 to P-a13 and P-b1 to P using the same method as in Example 1, except that the types and contents of each component were as described in Tables 1 to 4. A pellet of -b8 was obtained.

Using the pellets of the polyamide resin compositions obtained in Examples and Comparative Examples, molded articles were produced by the above methods, and various physical properties and evaluations were performed. Evaluation results are shown in Tables 1 to 4 below.

From Tables 1 to 4, the polyamide resin compositions Pa1 to Pa13 (Examples 1 to 13) are excellent in blow moldability, and heat resistance and chemical resistance when molded. .
Polyamide resin composition Pa1 (Example 1), polyamide resin composition Pa2 (Example 2) and polyamide resin composition Pa3 (Example 3), polyamide resin composition Pa4 (Example 4 ) and polyamide resin composition Pa5 (Example 5), and polyamide resin composition Pa11 (Example 11), polyamide resin composition Pa12 (Example 12) and polyamide resin composition Pa13 By comparing (Example 13), it can be seen that blow moldability (particularly parison sagging and swelling behavior) tends to become better as the content of ethylene-maleic acid derivative random copolymer B-1 increases. was taken.
In the polyamide resin composition Pa1 (Example 1), the polyamide resin composition Pa4 (Example 4) and the polyamide resin composition Pa6 (Example 6), the content of the polyamide resin A-2 was increased. Blow moldability (especially, surface smoothness) tended to be better along with the increase.
In the polyamide resin compositions Pa1 to Pa6 and Pa9 to Pa13 (Examples 1 to 6 and 9 to 13), the polyamide resin compositions Pa1 to Pa in which polyamide 66 and polyamide 6 were used in combination In Pa6 (Examples 1 to 6), there is a tendency that the heat aging resistance is further improved, while polyamide resin compositions Pa9 to Pa13 (Examples 1 to 6) using a combination of polyamide 66 and polyamide 612 9 to 13) tended to improve in chemical resistance.

On the other hand, the polyamide resin compositions P-b1 to P-b8 (Comparative Examples 1 to 8) were not excellent in terms of blow moldability, heat aging resistance and chemical resistance when molded. .

According to the polyamide resin composition of the present embodiment, it is possible to provide a polyamide resin composition which is excellent in blow moldability, heat aging resistance and chemical resistance when molded. The method for producing a molded article of the present embodiment is a method using the polyisocyanate composition, and the molded article obtained is for automobiles, machinery industry, electrical/electronics, industrial materials, industrial materials, and daily use. And it can be used as a material for various parts such as household items.

Claims (14)

(A-1) Polyamide 66;
(A-2) a polyamide resin other than polyamide 66;
(B) ethylene-maleic acid derivative random copolymer and E/X/Y terpolymer (wherein E is ethylene, X is vinyl acetate, and one selected from the group consisting of (meth)acrylic acid and its derivatives A polyamide resin composition containing one or more copolymers (excluding ionomers) selected from the group consisting of the above monomers (monomers) and Y being a maleic anhydride derivative, ,
The content of ethylene units is 85% by mass or more and 97% by mass or less with respect to the total mass of all structural units constituting the copolymer,
Content of one or more maleic acid derivative units selected from the group consisting of maleic acid monoesters, maleic acid diesters, fumaric acid monoesters, and fumaric acid diesters, relative to the total mass of all structural units constituting the copolymer is 3% by mass or more and 15% by mass or less,
(A-2) the polyamide resin other than polyamide 66 has a melting point of 210° C. or higher and 340° C. or lower;
The mass ratio (A-2)/(A-1) of the (A-2) polyamide resin other than polyamide 66 to the (A-1) polyamide 66 is 5/95 or more and 95/5 or less,
The content of the copolymer is 5 parts by mass or more and 30 parts by mass or less with respect to the total mass of 100 parts by mass of the (A-1) polyamide 66 and the (A-2) polyamide resin other than polyamide 66. the law of nature,
(A-2) A polyamide resin composition, wherein the polyamide resin other than polyamide 66 is polyamide 6 or polyamide 612 . Among polyamide resins other than (A-1) polyamide 66 and (A-2) polyamide resins other than polyamide 66, tan δ measured by a rotary rheometer at the melting point +10° C. of the polyamide resin having the highest melting point satisfies the following formula: The polyamide resin composition according to claim 1.

(In the formula, tan δ (1) represents tan δ when measured at an angular velocity of 1 rad/sec, and tan δ (100) represents tan δ when measured at an angular velocity of 100 rad/sec.) The content of the copolymer is 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the total mass of the (A-1) polyamide 66 and the (A-2) polyamide resin other than polyamide 66. , The polyamide resin composition according to claim 1 or 2. (C) The polyamide resin composition according to any one of claims 1 to 3 , further comprising an inorganic filler. (D) further containing an alkali metal salt,
The content of the (D) alkali metal salt is 0.01 parts by mass or more with respect to 100 parts by mass of the total mass of the (A-1) polyamide 66 and the (A-2) polyamide resin other than the polyamide 66 2 The polyamide resin composition according to any one of claims 1 to 4 , which is 1 part by mass or less. 6. The polyamide resin composition according to claim 5 , wherein (D) the alkali metal salt is sodium carbonate or sodium hydrogen carbonate. (E) The polyamide resin composition according to any one of claims 1 to 6 , further comprising a neutralizing agent. (F) further containing elemental iron;
The content of the (F) elemental iron is 0.05 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the total mass of the (A-1) polyamide 66 and the (A-2) polyamide resin other than the polyamide 66 The polyamide resin composition according to any one of claims 1 to 7 , wherein: (G) copper halide, and (H) one or more halides selected from the group consisting of alkali metal halides and alkaline earth metal halides. The polyamide resin composition according to Item. A method for producing a molded product, comprising molding the polyamide resin composition according to any one of claims 1 to 9 by blow molding. 11. The method for producing a molded article according to claim 10 , wherein the molded article has a hollow shape. 12. The method for producing a molded article according to claim 10 , wherein the molded article is a material part for automobiles. 13. The method of manufacturing a molded article according to claim 12 , wherein said molded article is a turbo duct. 13. The method of manufacturing a molded article according to claim 12 , wherein the molded article is a battery cooling pipe.