JP6255188B2 - Polyamide resin composition and molded product - Google Patents

Description

  The present invention relates to a polyamide resin composition and a molded article.

Polyamide resins are excellent in strength, heat resistance, and chemical resistance, and have a high specific gravity, that is, a specific gravity smaller than that of metals, so that they have been conventionally used as metal substitute materials in automobile mechanical parts and the like.
In particular, since members around the engine are required to have durability under a high temperature environment, various polyamide resin compositions having excellent heat aging resistance have been proposed (see, for example, Patent Documents 1 and 2). .

In recent years, downsizing of automobiles has been performed as one means for improving fuel consumption. This tends to increase the density of parts in the automobile engine room and increase the environmental temperature in the engine room.
In addition, in order to improve fuel efficiency, the engine output is increased by a supercharger, and accordingly, the environmental temperature in the engine room tends to become higher.
Accordingly, polyamide resins are required to have long-term heat aging resistance under higher temperature conditions than before.

As a technique for improving the heat aging resistance of a polyamide resin, a technique of adding a copper compound (copper oxide or salt) is known.
Similarly, as a technique for improving the heat aging resistance, a technique in which a copper compound and iron oxide are blended with two types of polyamides having different melting points (see, for example, Patent Document 3), and a technique in which fine elemental iron is blended with polyamide. (For example, refer patent document 4) and the technique (For example, refer patent document 5) which mix | blends the fine dispersion metal powder with polyamide is disclosed.

  On the other hand, a polyamide resin composition to which sodium aluminate is added and a method for producing the same are disclosed (for example, see Patent Documents 6 to 8).

Special table 2013-501095 gazette Special table 2013-521393 gazette Special table 2008-527129 JP-T-2006-528260 Special table 2008-527127 JP 2007-246647 A JP 2004-91778 A JP-A-49-116151

However, in the techniques described in Patent Documents 1 to 8, a polyamide resin composition having a high level of heat aging resistance has not yet been obtained.
That is, a polyamide resin composition excellent in resistance to thermal oxidation that can retain practically sufficient mechanical properties when left for a long time under a high temperature condition while maintaining the shape of the molded body has not yet been obtained. .

  In view of the above-described problems of the prior art, an object of the present invention is to provide a polyamide resin composition having excellent heat aging resistance and a molded product thereof.

As a result of intensive studies to solve the above problems, the inventors of the present invention include (A) a polyamide resin and (B) a metal aluminate, and (B) 100 parts by mass of the (A) polyamide resin. 1 part by mass or more, and (B) the metal aluminate salt includes a polyamide resin composition having a particle size of 1 μm or more and a content of 20% by mass or less, and the polyamide resin composition. The present inventors have found that a molded article can solve the above-mentioned problems and have completed the present invention.
That is, the present invention is as follows.

[1]
(A) a polyamide resin;
(B) a metal aluminate salt;
Including
(B) 2 parts by mass or more of (B) metal aluminate is contained with respect to 100 parts by mass of (A) polyamide resin,
(B) The polyamide resin composition in which particles of aluminate metal salt having a particle diameter of 1 μm or more are 15% by mass or less in the metal aluminate salt.
[2]
(B) The polyamide resin composition according to [1], wherein the metal aluminate salt is sodium aluminate.
[3]
Containing a reducing phosphorus compound,
The polyamide resin composition according to [1] or [2], wherein the content of the reducing phosphorus compound is 200 ppm or less in terms of the content of phosphorus element.
[4]
The ratio (amino end group concentration (μmol / g) / carboxyl end group concentration (μmol / g)) between the amino end group concentration and the carboxyl end group concentration in the (A) polyamide resin is as follows:
The polyamide resin composition according to any one of [1] to [3], which is 0.2 to 1.8.
[5]
The polyamide resin (A) is polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610, polyamide 612.
, Polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonanemethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide) and polyamide MXD6 (polymetaxylylene adipamide) and copolymers containing these as constituents [1] to [4], which are at least one selected from the group consisting of polyamides.
] The polyamide resin composition as described in any one of.
[6]
(C) The polyamide resin composition according to any one of [1] to [5], further including glass fibers.
[7]
The (C) glass fiber is a copolymer comprising a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as constituent units. The polyamide resin composition according to [6], which is included as a part of a component applied to the surface of the glass fiber.
[8]
A molded article comprising the polyamide resin composition according to any one of [1] to [7].

  ADVANTAGE OF THE INVENTION According to this invention, the polyamide resin composition excellent in heat aging property and its molded article can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described 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 implemented with appropriate modifications within the scope of the gist.

[Polyamide resin composition]
The polyamide resin composition of this embodiment is
(A) a polyamide resin;
(B) a metal aluminate salt;
Including
The (B) metal aluminate is contained in an amount of 1 part by mass or more with respect to 100 parts by mass of the (A) polyamide resin,
In (B) the aluminate metal salt, particles of the aluminate metal salt having a particle diameter of 1 μm or more are 20% by mass or less.
By setting it as the structure mentioned above, the polyamide resin composition of this embodiment can exhibit the outstanding heat aging property.

Each component of the polyamide resin composition of this embodiment is demonstrated in detail.
((A) Polyamide resin)
The polyamide resin composition of this embodiment contains (A) a polyamide resin (hereinafter, may be referred to as polyamide resin, polyamide, (A) component, (A)).
“Polyamide resin” means a polymer compound having a —CO—NH— (amide) bond in the main chain.
As (A) polyamide resin, for example, (a) polyamide obtained by ring-opening polymerization of lactam, (b) polyamide obtained by self-condensation of ω-aminocarboxylic acid, (c) diamine and dicarboxylic acid are condensed. However, it is not limited to these.
Moreover, as (A) polyamide resin, only 1 type of the said polyamide may be used independently, and you may use as a 2 or more types of mixture.

  (A) When the polyamide obtained by the ring-opening polymerization of (a) lactam is used as the polyamide resin, the lactam as a monomer constituting the component (A) of the polyamide resin is not limited to the following. Examples thereof include pyrrolidone, caprolactam, undecaractam, dodecaractam and the like.

  (A) When the polyamide obtained by the self-condensation of (b) ω-aminocarboxylic acid is used as the polyamide resin, the ω-aminocarboxylic acid is not limited to the following. A ω-amino fatty acid which is a ring-opening compound with water can be used. The lactam or the ω-aminocarboxylic acid may be a product obtained by condensing two or more monomers (the lactam or the ω-aminocarboxylic acid) in combination.

(A) When the polyamide obtained by condensing the diamine and dicarboxylic acid is used as the polyamide resin, the diamine (monomer) is not limited to the following. Linear aliphatic diamines such as methylene diamine, pentamethylene diamine and nonane methylene diamine; branched aliphatic diamines such as 2-methylpentane diamine and 2-ethyl hexamethylene diamine; p-phenylene diamine and m-phenylene diamine And aromatic diamines such as m-xylylenediamine; and alicyclic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine.
The dicarboxylic acid (monomer) is not limited to the following, but examples thereof include aliphatic dicarboxylic acids such as adipic acid, pimelic acid, sebacic acid, and dodecanedioic acid; terephthalic acid, isophthalic acid, and the like. Aromatic dicarboxylic acids; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

  As the polyamide resin (A) obtained by using the polyamide obtained by condensing the diamine and the dicarboxylic acid (c), one kind is used alone, or two or more kinds of the diamine and dicarboxylic acid are used in combination. It may be a

  The polyamide obtained by condensing the diamine and dicarboxylic acid can be obtained, for example, by polymerizing an aqueous salt solution in which equimolar amounts of diamine and dicarboxylic acid are dissolved by dehydration condensation. In addition, it can superpose | polymerize by adjusting to suitable temperature and pressure by a conventionally well-known method.

  The polyamide resin (A) used in the polyamide resin composition of the present embodiment obtained as described above is not limited to the following, but examples include polyamide 4 (poly α-pyrrolidone), polyamide 6 (polycarbonate). Proamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610, polyamide 612, polyamide 6T (Polyhexamethylene terephthalamide), polyamide 9T (polynonanemethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), polyamide 2Me5T (poly-2-methylpentamethylene terephthalamide), and polyamide MXD (Poly meta-xylylene adipamide) and one or more polyamide resins selected from the group consisting of copolymerized polyamide containing at least one of these as a component, and the like.

  Examples of the copolyamide include, but are not limited to, for example, a copolymer of hexamethylene adipamide and hexamethylene terephthalamide, a copolymer of hexamethylene adipamide and hexamethylene isophthalamide, and Examples thereof include a copolymer of hexamethylene terephthalamide and 2-methylpentanediamine terephthalamide.

Among the polyamide resins, the polyamide resin (A) used in the polyamide resin composition of the present embodiment includes polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610, polyamide 612, polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonanemethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide) and polyamide MXD6 (polymetaxylylene adipamide) Polymerized polyamide is preferable, and a copolymer containing hexamethylene adipamide (polyamide 66) and polyamide 66 is more preferable.
By using the polyamide resin, the polyamide resin composition of the present embodiment tends to exhibit more excellent heat aging resistance.

The polyamide resin (A) used in the polyamide resin composition of the present embodiment is preferably contained in the polyamide resin composition in an amount of 33% by mass to 95% by mass, and contained in an amount of 50% by mass to 75% by mass. More preferably.
The polyamide resin composition of this embodiment tends to be excellent in strength, heat resistance, chemical resistance, specific gravity and the like by containing the (A) polyamide resin in the above range.

Polyamide has an end portion (polymer end) of a polymer chain obtained by polymerizing dicarboxylic acid and diamine by an amide bond, and has an amino end group and a carboxyl end group.
The amino terminal group is a polymer terminal to which an amino group (—NH ₂ group) is bonded, and is derived from a raw material diamine.
The carboxyl end group is a polymer end to which a carboxyl group (—COOH group) is bonded, and is derived from a raw material dicarboxylic acid.
In the polyamide resin composition of the present embodiment, (A) the ratio of the amino terminal group concentration to the carboxyl terminal group concentration of the polyamide resin (amino terminal group concentration (μmol / g) / carboxyl terminal group concentration (μmol / g)) is 0.2 to 1.8, preferably 0.3 to 1.6, and more preferably 0.4 to 1.4.
When the amino end group concentration / carboxyl end group concentration is 0.2 or more, high tensile strength tends to be exhibited. Further, when the amino terminal group concentration / carboxyl terminal group concentration is 1.8 or less, a polyamide resin composition more stable in heat retention tends to be obtained.
The amino end group concentration / carboxyl end group concentration can be controlled by adjusting the amount of amine monomer or carboxylic acid monomer added during polymerization.
Moreover, the density | concentration of a terminal group can be calculated | required by performing 1H-NMR measurement at 60 degreeC, for example using a bisulfuric acid solvent. That is, it can be calculated by determining the integrated values of the peaks respectively corresponding to the amino terminal group and the carboxyl terminal group obtained by the NMR measurement.
Specifically, it can be determined by the method described in Examples described later.

The sulfuric acid relative viscosity of the polyamide resin (A) used in the polyamide resin composition of the present embodiment is preferably 1.8 or more and 3.0 or less, and more preferably 2.2 or more and 2.8 or less.
When the sulfuric acid relative viscosity is 1.8 or more, a polyamide resin composition having more excellent mechanical properties tends to be obtained. Moreover, it exists in the tendency for the polyamide resin composition which was more excellent in fluidity | liquidity and external appearance because the said sulfuric acid relative viscosity is 3.0 or less.
The sulfuric acid relative viscosity can be controlled by adjusting the pressure during polymerization of the (A) polyamide resin. The sulfuric acid relative viscosity can be measured by the method described in JIS K 6920. Specifically, it can be determined by the method described in Examples described later.

((B) Metal aluminate)
The polyamide resin composition of the present embodiment contains (B) a metal aluminate salt (hereinafter referred to as component (B) or (B) in some cases).
(B) Content of a metal aluminate is 1 mass part or more with respect to 100 mass parts of said (A) polyamide resins.
From the viewpoint of obtaining good heat aging resistance and initial strength, the (B) metal aluminate is preferably contained in an amount of 1 part by mass to 5 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. From the same viewpoint, 1 part by mass or more and 4 parts by mass or less are more preferable, 1 part by mass or more and 3 parts by mass or less are more preferable, and 1.2 parts by mass or more and 3 parts by mass or less are even more preferable.
Examples of (B) metal aluminate salts include, but are not limited to, lithium aluminate, sodium aluminate, potassium aluminate, beryllium aluminate, magnesium aluminate, and calcium aluminate. (B) As a metal aluminate, only 1 type in the above-mentioned may be used independently, and you may use as a 2 or more types of mixture.
From the viewpoint of stability during production, alkali metal aluminates are preferred, and sodium aluminate is more preferred.

In the polyamide resin composition of the present embodiment, (B) the aluminate metal salt has a particle content of 20 mass% or less in the (B) aluminate metal salt with a particle diameter of 1 μm or more. It is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less.
In the polyamide resin composition of the present embodiment, excellent heat aging resistance can be obtained when the content of particles of metal aluminate having a particle diameter of 1 μm or more is 20% by mass or less in the component (B). .
Here, the particle diameter of the metal aluminate salt is the particle diameter of the metal aluminate salt present in the polyamide resin composition of the present embodiment.
The particle diameter of the metal aluminate salt in the polyamide resin composition can be measured, for example, by dissolving the polyamide resin composition in formic acid and using a laser diffraction particle size distribution apparatus.

As described above, in order to suppress the content of particles of aluminate metal salt having a particle size of 1 μm or more in (B) metal aluminate salt to 20% by mass or less, (B) It is effective to mix a metal aluminate and (B) a polyamide resin. For example, a method in which (B) a metal aluminate salt is melt-kneaded with (A) a polyamide resin using an extruder may be mentioned.
On the other hand, when (B) the aluminate metal salt is contained in the condensation polymerization step of (A) the polyamide resin, the (B) metal aluminate salt may be increased in diameter. That is, (A) the polyamide resin polymerization step is completed, (A) the polyamide resin is taken out, and the component (A) and the component (B) are mixed at the stage of melt kneading, which is a manufacturing process of the polyamide resin composition. preferable.

((C) Glass fiber)
It is preferable that the polyamide resin composition of this embodiment contains (C) glass fiber (Hereinafter, it may describe as (C) component and (C).).
The content of the component (C) is preferably 5 parts by mass or more and 200 parts by mass or less, more preferably 5 parts by mass or more and 150 parts by mass or less, with respect to 100 parts by mass of the (A) polyamide resin. More preferably, it is set to not less than 100 parts by mass.
By setting it within the above range, both the fluidity and appearance characteristics of the polyamide resin composition of the present embodiment tend to be more excellent.
As the component (C) described above, only one type may be used alone, or two or more types may be used in combination.

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

Here, the number average fiber diameter and the weight average fiber length in the present specification can be determined as follows.
That is, the polyamide resin composition is put in an electric furnace, the contained organic matter is incinerated, and, for example, 100 or more (C) glass fibers are arbitrarily selected from the residue, and these fiber diameters are observed by SEM. The number average fiber diameter can be obtained by measuring the above and calculating the average value.
Further, the fiber length is measured using an SEM photograph at a magnification of 1000 times, and a predetermined calculation formula (when n fiber lengths are measured, weight average fiber length = Σ (i = 1 → n) (nth fiber Fiber length) ² / Σ (i = 1 → n) (fiber length of n-th fiber)), the weight average fiber length can be determined.

The glass fiber (C) may be surface-treated with a silane coupling agent or the like.
Examples of the silane coupling agent include, but are not limited to, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyl. Examples include aminosilanes such as dimethoxysilane; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes.
A silane coupling agent may be used individually by 1 type, and may use 2 or more types together. Among the silane coupling agents, aminosilanes are more preferable from the viewpoint of affinity with the resin.

The (C) glass fiber preferably further contains a sizing agent.
Here, the sizing agent is a component applied to the surface of the glass fiber.
As the sizing agent, a copolymer containing a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as a structural unit, an epoxy compound, Examples thereof include polycarbodiimide compounds, polyurethane resins, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines.
These sizing agents may be used alone or in combination of two or more.
Among these, from the viewpoint of mechanical strength of the polyamide resin composition of the present embodiment, the unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated vinyl monomer. Is preferably a copolymer, an epoxy compound, a polycarbodiimide compound and a polyurethane resin, and a combination thereof, a carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated vinyl monomer A copolymer containing an unsaturated vinyl monomer excluding the body as a constituent unit is more preferable.

Among the copolymers containing the carboxylic anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer excluding the carboxylic anhydride-containing unsaturated vinyl monomer as constituent units, the carboxylic anhydride The contained unsaturated vinyl monomer is not limited to the following, and examples thereof include maleic anhydride, itaconic anhydride and citraconic anhydride, and maleic anhydride is preferable.
On the other hand, the unsaturated vinyl monomer excluding the carboxylic anhydride-containing unsaturated vinyl monomer means an unsaturated vinyl monomer different from the carboxylic anhydride-containing unsaturated vinyl monomer.
The unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer is not limited to the following, for example, styrene, α-methylstyrene, ethylene, propylene, butadiene, isoprene, Examples include chloroprene, 2,3-dichlorobutadiene, 1,3-pentadiene, cyclooctadiene, methyl methacrylate, methyl acrylate, ethyl acrylate, and ethyl methacrylate. Of these, styrene and butadiene are preferred.
Among these combinations, selected from the group consisting of a copolymer of maleic anhydride and butadiene, a copolymer of maleic anhydride and ethylene, a copolymer of maleic anhydride and styrene, and a mixture thereof. It is more preferable that it is 1 type or more.

  Further, the copolymer containing the carboxylic acid anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as constituent units is the polyamide of this embodiment. From the viewpoint of improving the fluidity of the resin composition, the weight average molecular weight is preferably 2,000 or more. More preferably, it is 2,000-1,000,000, More preferably, it is 2,000-1,000,000. In addition, the weight average molecular weight in this specification can be measured by GPC (gel permeation chromatography).

  Examples of the epoxy compound include, but are not limited to, ethylene oxide, propylene oxide, butene oxide, pentene oxide, hexene oxide, heptene oxide, octene oxide, nonene oxide, decene oxide, undecenoxide, Aliphatic epoxy compounds such as dodecene oxide, pentadecene oxide, and eicosene oxide; 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, vinyl Alicyclic epoxy compounds such as hexene oxide and epoxidized cyclohexene methyl alcohol; Terpene epoxy compounds such as pinene oxide; Aromatic epoxy compounds such as styrene oxide, p-chlorostyrene oxide and m-chlorostyrene oxide; Epoxidized soybean oil And epoxidized linseed oil.

The polycarbodiimide compound is a compound obtained by condensing a compound containing one or more carbodiimide groups (—N═C═N—), that is, a carbodiimide compound.
The polycarbodiimide compound preferably has a degree of condensation of 1 to 20, and more preferably 1 to 10. When the degree of condensation is in the range of 1 to 20, a good aqueous solution or aqueous dispersion can be obtained. Furthermore, when the condensation degree is in the range of 1 to 10, a better aqueous solution or aqueous dispersion can be obtained.
Moreover, it is preferable that the said polycarbodiimide compound is a polycarbodiimide compound which has a polyol segment partially. By having a polyol segment partially, the polycarbodiimide compound is easily water-soluble and can be more suitably used as a glass fiber sizing agent.

  The carbodiimide compound, that is, the compound containing the various carbodiimide groups (—N═C═N—) is a diisocyanate compound, a known carbodiimidization catalyst such as 3-methyl-1-phenyl-3-phospholene-1-oxide. It can be obtained by decarboxylation in the presence of.

As the diisocyanate compound, aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates, and mixtures thereof can be used.
Examples of the isocyanate compound include, but are not limited to, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1 , 4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture 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 Sulfonates, such as 2,6-diisopropylphenyl isocyanate and 1,3,5-triisopropylbenzene 2,4-diisocyanate.
And carbodiimide compound which has two isocyanate groups at the terminal is obtained by carbodiimidizing these diisocyanate compounds. Of these, dicyclohexylmethane carbodiimide can be suitably used from the viewpoint of improving reactivity.

In addition, a polycarbodiimide compound having one isocyanate group at the end is obtained by a method of carbodiimidizing a monoisocyanate compound or a method of reacting with a polyalkylene glycol monoalkyl ether to generate a urethane bond. It is done.
Examples of the monoisocyanate compound include, but are not limited to, hexyl isocyanate, phenyl isocyanate, and cyclohexyl isocyanate.
Examples of the polyalkylene glycol monoalkyl ether described above include, but are not limited to, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, and the like.

  The polyurethane resin is not particularly limited as long as it is generally used as a sizing agent. For example, m-xylylene diisocyanate (XDI), 4,4′-methylenebis (cyclohexyl isocyanate). Nart) (HMDI), isophorone diisocyanate (IPDI) and the like, and those synthesized from polyester or polyether diols.

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

The “other copolymerizable monomer” that forms a copolymer of the acrylic acid and another copolymerizable monomer is not limited to the following, but, for example, a monomer having a hydroxyl group and / or a carboxyl group Among them, one or more selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, vinyl acetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid and mesaconic acid are mentioned (provided that acrylic acid is used) Except for only).
In addition, it is preferable to have 1 or more types of ester monomers among the monomers described above.

The aforementioned acrylic acid polymers (including both homopolymers and copolymers) may be in the form of salts.
The polymer salt of acrylic acid includes, but is not limited to, primary, secondary or tertiary amines.
Specific examples include triethylamine, triethanolamine, and glycine.
The degree of neutralization is preferably 20 to 90%, preferably 40 to 60% from the viewpoint of improving the stability of the mixed solution with other concomitant drugs (such as a silane coupling agent) and reducing the amine odor. Is more preferable.
The weight average molecular weight of the acrylic acid polymer forming the salt is not particularly limited, but is preferably in the range of 3,000 to 50,000. 3,000 or more are preferable from the viewpoint of improving the converging property of the glass fiber, and 50,000 or less are preferable from the viewpoint of improving the mechanical properties of the polyamide resin composition of the present embodiment.

As a method for treating glass fiber with the various sizing agents described above, the sizing agent described above is applied to the glass fiber by using a known method such as a roller-type applicator in a known glass fiber manufacturing process. The method of making it react continuously by drying the used fiber strand is mentioned.
The fiber strand may be used as a roving as it is, or may be used as a chopped glass strand by further obtaining a cutting step.
The sizing agent is preferably applied (added) as a solid content of 0.2 to 3% by mass, more preferably 0.3 to 2% by mass (added) with respect to 100% by mass of the glass fiber. From the viewpoint of maintaining the bundling of the glass fiber, it is preferable that the addition amount of the bundling agent is 0.2% by mass or more as a solid content with respect to 100% by mass of the glass fiber. On the other hand, it is preferable that it is 3 mass% or less from a viewpoint of the thermal-stability improvement of the polyamide resin composition of this embodiment.
The strand may be dried after the cutting step, or after the strand is dried, the cutting step may be performed.

(Other ingredients)
The polyamide resin composition of the present embodiment may further contain other components as necessary within the range not impairing the effects of the present invention, in addition to the components (A) to (C) described above.
Examples of the other components include, but are not limited to, inorganic fillers such as carbon fiber and talc, ultraviolet absorbers, photodegradation inhibitors, plasticizers, lubricants, mold release agents, nucleating agents, difficulty Examples include flame retardants, colorants, dyes and pigments, and other thermoplastic resins. Here, since the above-mentioned other components are greatly different in properties, there are various suitable contents for each component that hardly 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.

In the polyamide resin composition of the present embodiment, the content of the reducing phosphorus compound is preferably 200 ppm or less in terms of the phosphorus element content.
Since the content of the reducing phosphorus compound is 200 ppm or less in terms of the content of phosphorus element, (B) the denaturation of the aluminate metal salt is suppressed, so that the polyamide resin having better heat aging resistance A composition is obtained.
From the same viewpoint, the content of the reducible phosphorus compound is more preferably 100 ppm or less in terms of the content of the phosphorus element, and the content of the reducible phosphorus compound in terms of the content of the phosphorus element. It is more preferably 60 ppm or less, and further preferably 1 ppm or less, which is the detection limit.

[Production method of polyamide resin composition]
The polyamide resin composition of the present embodiment can be produced by mixing (A) a polyamide resin, (B) a metal aluminate, and (C) glass fiber and other components as necessary.
In the production of the polyamide resin composition, a method of kneading the metal aluminate (B) in a state where (A) the polyamide resin is melted by a single-screw or multi-screw extruder can be preferably used. In addition, a mixture of (B) an aqueous solution of metal aluminate and (B) polyamide resin pellets is thoroughly stirred and mixed, and then dried by moisture, and then a mixture of polyamide resin pellets and metal aluminate is extruded. A method of supplying and melting and kneading from the supply port of the machine can be used.
(B) From the viewpoint of dispersibility of the metal aluminate salt, (B) the addition of the metal aluminate salt is carried out in the state where (A) the polyamide resin is melted by a single-screw or multi-screw extruder, A method of kneading a metal aluminate salt is preferred.

[Molded body]
The molded body of the present embodiment includes the polyamide resin composition according to the above-described embodiment.
Although the molded object of this embodiment is not specifically limited, For example, it is obtained by injection-molding a polyamide resin composition.
The molded body in the present embodiment is not limited to the following, but for example, various types such as for automobiles, machine industry, electrical / electronic, industrial materials, industrial materials, daily / household goods, etc. Can be applied to parts.
The molded body of the present embodiment has excellent heat aging resistance for the various parts described above.

Hereinafter, the present invention will be described in detail with specific examples and comparative examples, but the present invention is not limited to the following examples.
In addition, the measuring method for evaluating the sample which concerns on an Example and a comparative example is as follows.

〔Measuring method〕
(98% sulfuric acid relative viscosity (ηr))
The 98% sulfuric acid relative viscosity (ηr) of the (A) polyamide resin in Examples and Comparative Examples (hereinafter also simply referred to as “examples”) to be described later was measured according to JISK6920.

(End group concentration)
The end group concentration of the (A) polyamide resin in Examples and Comparative Examples described later was obtained by 1H-NMR measurement at 60 ° C. using a bisulfuric acid solvent.
As a measuring device at this time, ECA500 manufactured by JEOL Ltd. was used.
That is, the terminal group concentration was calculated from the integrated value of the corresponding peak of the amino terminal group and carboxyl terminal group of (A) polyamide resin in each example.

(Initial tensile strength)
Using the injection molding machine (PS-40E: made by Nissei Resin Co., Ltd.), the pellets of the polyamide resin composition produced in the examples and comparative examples were molded into a multipurpose test piece (A type) while conforming to ISO 3167. A piece was molded.
At that time, the injection and pressure holding time was set to 25 seconds and the cooling time was set to 15 seconds.
Moreover, the mold temperature and the cylinder temperature were set to the temperatures described in the later-described (A) polyamide resin production example.
Using the obtained multipurpose test piece (A type), a tensile test was performed at a tensile speed of 5 mm / min in accordance with ISO 527, and a tensile strength (MPa) was measured.

(Heat resistant aging)
The multipurpose test piece (A type) in the above (Initial tensile strength) was heat-aged at 230 ° C. in a hot air circulation oven.
After a predetermined time, it was taken out from the oven, cooled at 23 ° C. for 24 hours or more, then subjected to a tensile test at a tensile speed of 5 mm / min in accordance with ISO 527, and each tensile strength (MPa) was measured. By this method, the time (h: hour) at which the tensile strength was reduced by half was determined.

(LLC resistance)
The multipurpose test piece (A type) in the above (initial tensile strength) was immersed in an LLC solution at 120 ° C.
As the LLC solution, Toyota Genuine Super LLC 50% aqueous solution was used.
After a predetermined test time, the test piece was taken out from the LLC solution and then left at 23 ° C. for 1 hour or longer.
Thereafter, a tensile test was performed at a tensile speed of 5 mm / min while conforming to ISO 527, and each tensile strength (MPa) was measured.
By this method, the time (h: hour) at which the tensile strength was reduced by half was determined.

(Charpy impact strength with notch)
The multipurpose test piece (A type) is cut and used, and a notched Charpy impact strength (kJ / m ²⁾ using a test piece having a thickness of 80 mm × width of 10 mm × length of 4 mm while conforming to ISO 179. ) Was measured.

(Evaluation of color tone (b value))
The b value of the multipurpose test piece (A type) corresponding to each example was measured by a reflection method using a color difference meter ZE-2000 manufactured by Nippon Denshoku.

(Phosphorus element concentration and reducing phosphorus element concentration in polyamide resin)
<(1) Concentration of phosphorus element>
A sample of 0.5 g was weighed, 20 mL of concentrated sulfuric acid was added, and wet decomposition was performed on a heater.
After cooling, 5 mL of hydrogen peroxide was added, heated on a heater, and concentrated until the total amount was 2-3 mL.
The solution was cooled again to 500 mL with pure water.
The apparatus was quantified at a wavelength of 213.618 (nm) by high frequency inductively coupled plasma (ICP) emission analysis using IRIS / IP manufactured by Thermo Jarrel Ash.
The concentration of phosphorus element was expressed as the concentration CP (mol) of phosphorus element with respect to 10 ⁶ g of polyamide resin using this quantitative value.

<(2) Concentration of hypophosphite ion, phosphite ion, phosphate ion>
Add 100 mL of water to 50 g of sample, separate after ultrasonic treatment at room temperature for 15 minutes, obtain a filtrate, and then use a Hewlett Packard capillary electrophoresis apparatus (HP3D) to perform hypophosphite ion, The concentration (molar) ratio of phosphate ion and phosphate ion was measured.
The concentration ratio was calculated by measuring a hypophosphite ion standard solution, a phosphite ion standard solution, and a phosphate ion standard solution with known concentrations in the same manner to create a calibration curve.

The concentration X of the reducing phosphorus element was determined by converting to the molar amount of phosphorus with respect to 10 ⁶ g of polyamide using the following formula.

Reducing phosphorus element concentration X = CP × (CP1 + CP2) / (CP1 + CP2 + CP3)
CP: concentration of phosphorus element (mole) with respect to 10 ⁶ g of polyamide obtained in (1)
CP1: Concentration (molar) ratio of hypophosphite ion obtained in (2) CP2: Concentration (molar) ratio of phosphite ion obtained in (2) CP3: Concentration of phosphate ion obtained in (2) (Mole) ratio

((B) Measurement of particle diameter of metal aluminate)
10 g of the polyamide resin composition was dissolved in 10 mL of formic acid (manufactured by Wako Pure Chemical Industries).
The solution was measured using a laser diffraction particle size distribution analyzer (SALD-7000) manufactured by Shimadzu Corporation.
The optimum refractive index for the metal compound was selected. For example, in the case of sodium aluminate, it was set to 1.60-1.00i.
The particle size was determined by measuring the particle size distribution in terms of volume using software attached to the apparatus.

〔material〕
The raw materials used in the examples and comparative examples are as follows.
((A) Polyamide resin)
<Polyamide resin A-1 (PA66)>
30 kg of an aqueous solution of an equimolar salt of 50% by mass of hexamethylenediamine and adipic acid was prepared and sufficiently stirred.
An aqueous solution of the raw material of the polyamide 66 (hereinafter sometimes simply referred to as an aqueous solution of the raw material) was charged into a 70 L autoclave having a stirring device and having a discharge nozzle at the bottom.
Thereafter, the mixture was sufficiently stirred at a temperature of 50 ° C.
Next, the atmosphere was replaced with nitrogen, and then the temperature was raised from 50 ° C. to about 270 ° C. with stirring. At this time, heating was continued for about 1 hour while removing water from the system so that the pressure in the autoclave was maintained at about 1.77 MPa.
Thereafter, the pressure was reduced to atmospheric pressure over about 1 hour, and further maintained at about 270 ° C. and atmospheric pressure for about 1 hour, and then stirring was stopped.
The polymer was discharged in a strand form from the lower nozzle, and water cooling and cutting were performed to obtain pellets.
<Polyamide resin A-1> had a 98% sulfuric acid relative viscosity of 2.8.
The amino end group concentration was 46 μmol / g, and the carboxyl end group concentration was 72 μmol / g.
That is, the amino end group concentration / carboxyl end group concentration was 0.64.
In the molding of the polyamide resin composition using <polyamide resin A-1>, the mold temperature was set to 80 ° C., and the cylinder temperature was set to 290 ° C.

<Polyamide resin A-2 (PA66)>
An additional 900 g of adipic acid was added to the aqueous raw material solution. For other conditions, <polyamide resin A-2> was produced by the same production method as in <polyamide resin A-1>.
<Polyamide resin A-2> had a 98% sulfuric acid relative viscosity of 2.2. The amino end group concentration was 33 μmol / g, and the carboxyl end group concentration was 107 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.3. In the molding of the polyamide resin composition using <polyamide resin A-2>, the mold temperature was set to 80 ° C. and the cylinder temperature was set to 290 ° C.

<Polyamide resin A-3 (PA66)>
An additional 900 g of hexamethylenediamine was added to the aqueous solution of the raw material. For other conditions, <polyamide resin A-3> was produced by the same production method as in <polyamide resin A-1>.
<Polyamide resin A-3> had a 98% sulfuric acid relative viscosity of 2.4. The amino end group concentration was 78 μmol / g, and the carboxyl end group concentration was 52 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 1.5. In the molding of the polyamide resin composition using <polyamide resin A-3>, the mold temperature was set to 80 ° C. and the cylinder temperature was set to 290 ° C.

<Polyamide resin A-4 (PA66 / 6T)>
<Polyamide resin A-4 (PA66 / 6T)> was produced according to the production example of JP 2013-501094 A.
<Polyamide resin A-4> had a 98% sulfuric acid relative viscosity of 2.9.
The amino end group concentration was 42 μmol / g, and the carboxyl end group concentration was 65 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.6.
In the molding of the polyamide resin composition using <polyamide resin A-4>, the mold temperature was set to 80 ° C. and the cylinder temperature was set to 290 ° C.

<Polyamide resin A-5 (PA610)>
<Polyamide resin A-5 (PA610)> was manufactured according to the manufacture example of Unexamined-Japanese-Patent No. 2011-148997.
<Polyamide resin A-5> had a 98% sulfuric acid relative viscosity of 2.3.
The amino end group concentration was 58 μmol / g, and the carboxyl end group concentration was 79 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.7.
In the molding of the polyamide resin composition using <polyamide resin A-5>, the mold temperature was set to 80 ° C., and the cylinder temperature was set to 260 ° C.

<Polyamide resin A-6 (PA9T)>
<Polyamide resin A-6 (PA9T)> was manufactured according to the manufacturing example of Unexamined-Japanese-Patent No. 2013-40346.
<Polyamide resin A-6> had a 98% sulfuric acid relative viscosity of 2.9.
The amino end group concentration was 42 μmol / g, and the carboxyl end group concentration was 52 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.8.
In molding the polyamide resin composition using <polyamide resin A-6>, the mold temperature was set to 120 ° C., and the cylinder temperature was set to 330 ° C.

((B) Metal aluminate)
<Sodium aluminate B-1>
Sodium aluminate manufactured by Wako Pure Chemical Industries, Ltd. was used.
<Magnesium aluminate B-2>
Sigma-Aldrich magnesium aluminate was used.

((C) Glass fiber)
(C-1 glass fiber)
In terms of solid content, 2% by mass of polyurethane resin (trade name: Bondic (registered trademark) 1050, manufactured by Dainippon Ink Co., Ltd.), ethylene-maleic anhydride copolymer (manufactured by Wako Pure Chemical Industries, Ltd.) 8% by mass, 0.6% by mass of γ-aminopropyltriethoxysilane (trade name: KBE-903, (manufactured by Shin-Etsu Chemical Co., Ltd.)), 0.1% by mass of lubricant (trade name: carnauba wax ( The product was diluted with water so that the total mass was adjusted to 100% by mass to obtain a glass fiber sizing agent.
The glass fiber sizing agent was attached to a melt-proofed glass fiber having a number average fiber diameter of 10 μm.
That is, the glass fiber sizing agent was applied to the glass fiber being wound around the rotating drum by using an applicator installed at a predetermined position. Next, this was dried to obtain a roving (glass roving) of a glass fiber bundle surface-treated with the glass fiber sizing agent. At that time, the glass fiber was made to be a bundle of 1,000 pieces.
The adhesion amount of the glass fiber sizing agent was 0.6% by mass. This was cut into a length of 3 mm to obtain a glass chopped strand. This chopped strand was used as <glass fiber D-1>.

(Reducible phosphate compound)
<Sodium hypophosphite>
A reagent manufactured by Taihei Chemical Industry Co., Ltd. was used.

[ Reference Example 1]
As the extruder, a twin screw extruder (ZSK-26MC: manufactured by Coperion (Germany)) was used.
This twin-screw extruder has an upstream supply port in the first barrel from the upstream side, and a downstream supply port in the ninth barrel. L / D (length of the cylinder of the extruder / cylinder diameter of the extruder) = 48 (number of barrels: 12).
In this twin-screw extruder, the temperature from the upstream supply port to the die was set to the cylinder temperature described in the above item ((A) polyamide resin).
Further, the screw rotation speed was set to 300 rpm, and the discharge amount was set to 25 kg / hour.
Under such conditions, from the upstream supply port so as to have the ratio described in the upper part of Table 1 below (
A) Polyamide resin and (B) metal aluminate are supplied, and (C) is supplied from the downstream supply port.
Glass fiber was supplied and melt-kneaded to produce resin composition pellets.
The obtained polyamide resin composition was molded, and the heat aging resistance, initial strength, and Charpy impact strength were evaluated using the molded piece. These evaluation results are shown in Table 1 below.

[ Reference Example 2, Examples 4 to 9, 12 to 19, Comparative Example 1]
According to the composition described in Table 1 to Table 5, the other conditions were the same as in Reference Example 1, and a polyamide resin composition was produced and molded. Using the molded piece, heat aging resistance, LCC resistance, Initial strength, Charpy impact strength, and color tone were evaluated. These evaluation results are shown in Tables 1 to 5 below.

Example 10
The screw speed was 250 rpm. For other conditions, a polyamide resin composition was produced and molded in the same manner as in Reference Example 1, and heat aging resistance and LCC resistance were evaluated using the molded pieces. The evaluation results are shown in Table 3 below.

Example 11
The screw speed was 200 rpm. For other conditions, a polyamide resin composition was produced and molded in the same manner as in Reference Example 1, and heat aging resistance and LCC resistance were evaluated using the molded pieces. The evaluation results are shown in Table 3 below.

[Comparative Example 2]
The screw speed was 150 rpm. For other conditions, a polyamide resin composition was produced and molded in the same manner as in Reference Example 1, and heat aging resistance and LCC resistance were evaluated using the molded pieces. The evaluation results are shown in Table 3 below.

[Comparative Example 3]
30 kg of an aqueous solution of an equimolar salt of 50% by mass of hexamethylenediamine and adipic acid was prepared and sufficiently stirred.
The aqueous solution of the raw material of the polyamide 66 was charged into a 70 L autoclave having a stirrer and an extraction nozzle at the bottom.
Subsequently, sodium aluminate was added to 2 parts by mass with respect to 100 parts by mass of the polyamide resin.
Thereafter, the mixture was sufficiently stirred at a temperature of 50 ° C.
Next, the atmosphere was replaced with nitrogen, and then the temperature was raised from 50 ° C. to about 270 ° C. with stirring. At this time, heating was continued for about 1 hour while removing water from the system so that the pressure in the autoclave was maintained at about 1.77 MPa.
Thereafter, the pressure was reduced to atmospheric pressure over about 1 hour, and further maintained at about 270 ° C. and atmospheric pressure for about 1 hour, and then stirring was stopped.
The polymer was discharged in a strand form from the lower nozzle, and water cooling and cutting were performed to obtain pellets.
The resin had a 98% sulfuric acid relative viscosity of 2.8. The amino end group concentration was 46 μmol / g, and the carboxyl end group concentration was 72 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.64.

[Comparative Example 4]
30 kg of an aqueous solution of an equimolar salt of 50% by mass of hexamethylenediamine and adipic acid was prepared and sufficiently stirred.
The aqueous solution of the raw material of the polyamide 66 was charged into a 70 L autoclave having a stirrer and an extraction nozzle at the bottom.
Subsequently, sodium aluminate was added to 2 parts by mass with respect to 100 parts by mass of the polyamide resin. Furthermore, ammonium polyacrylate was added to 4 parts by mass with respect to 100 parts by mass of the polyamide resin.
Thereafter, the mixture was sufficiently stirred at a temperature of 50 ° C.
Next, the atmosphere was replaced with nitrogen, and then the temperature was raised from 50 ° C. to about 270 ° C. with stirring. At this time, heating was continued for about 1 hour while removing water from the system so that the pressure in the autoclave was maintained at about 1.77 MPa.
Thereafter, the pressure was reduced to atmospheric pressure over about 1 hour, and further maintained at about 270 ° C. and atmospheric pressure for about 1 hour, and then stirring was stopped.
The polymer was discharged in a strand form from the lower nozzle, and water cooling and cutting were performed to obtain pellets.
The resin had a 98% sulfuric acid relative viscosity of 2.8. The amino end group concentration was 46 μmol / g, and the carboxyl end group concentration was 72 μmol / g. That is, the amino end group concentration / carboxyl end group concentration was 0.64.
The above method uses the method described in Example 1 of Japanese Patent Application Laid-Open No. 2007-246647. By adding ammonium polyacrylate, the amount of the component (B) having a particle diameter of 1 μm or more was reduced as compared with Comparative Example 3.
However, even if this method is used, (A) a polyamide resin and (B) a metal aluminate salt are included, and the (B) metal aluminate is contained in 100 parts by mass of the (A) polyamide resin. In the polyamide resin composition contained in an amount of 1 part by mass or more, it was not possible to achieve 20% by mass or less of metal aluminate particles having a particle diameter of 1 μm or more.

From Tables 1 to 5, it was found that the polyamide resin compositions of Reference Examples 1 and 2 and Examples 4 to 19 exhibited excellent heat aging resistance. On the other hand, Comparative Examples 1 to 4 were inferior in heat aging resistance as compared with the Examples.

  The polyamide resin composition of the present invention has industrial applicability as a material for various parts such as those for automobiles, machinery industries, electric / electronics, industrial materials, industrial materials, daily use / household goods, etc. is there.

Claims (8)

(A) a polyamide resin;
(B) a metal aluminate salt;
Including
(B) 2 parts by mass or more of (B) metal aluminate is contained with respect to 100 parts by mass of (A) polyamide resin,
(B) The polyamide resin composition in which particles of aluminate metal salt having a particle diameter of 1 μm or more are 15% by mass or less in the metal aluminate salt. The polyamide resin composition according to claim 1, wherein the (B) metal aluminate salt is sodium aluminate. Containing a reducing phosphorus compound,
The polyamide resin composition according to claim 1 or 2, wherein the content of the reducing phosphorus compound is 200 ppm or less in terms of the content of phosphorus element. The ratio (amino end group concentration (μmol / g) / carboxyl end group concentration (μmol / g)) between the amino end group concentration and the carboxyl end group concentration in the (A) polyamide resin is as follows:
The polyamide resin composition according to any one of claims 1 to 3, wherein the polyamide resin composition is 0.2 or more and 1.8 or less. The polyamide resin (A) is polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610, polyamide 612.
, Polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonanemethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide) and polyamide MXD6 (polymetaxylylene adipamide) and copolymers containing these as constituents The polyamide resin composition according to any one of claims 1 to 4, which is at least one member selected from the group consisting of polyamides. (C) The polyamide resin composition according to any one of claims 1 to 5, further comprising glass fibers. The (C) glass fiber is a copolymer comprising a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as constituent units. The polyamide resin composition according to claim 6, which is included as a part of a component applied to the surface of the glass fiber.   A molded article comprising the polyamide resin composition according to any one of claims 1 to 7.