JP2019178261A - Polyamide composition and molded article - Google Patents

Abstract

To provide a polyamide composition excellent in rigidity and fluidity at water absorption, and capable of forming a molded article superior in surface appearance.SOLUTION: A polyamide composition includes 50-99 pts.mass of (A) aliphatic polyamide and 1-50 pts.mass of (B)semiaromatic polyamide including a dicarboxylic acid unit and a diamine unit, based on 100 pts.mass of the total mass of components (A) and (B). The component (A) includes at least one selected from the group consisting of the lactam unit having the carbon number of 4 to 14 and the aminocarboxylic acid unit having the carbon number of 4 to 14. The component (B) includes 75 mol% or more of isophthalic acid unit in the whole dicarboxylic acid unit composing the component (B), and includes 50 mol% or more of diamine unit having the carbon number of 4 to 10 in the whole diamine unit composing the component (B). The weight average molecular weight Mw of the polyamide composition is 15,000 or more but 35,000 or less.SELECTED DRAWING: None

Description

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

  In general, polyamide resins are excellent in mechanical properties, heat resistance, impact resistance, and chemical resistance, and are widely used in automobile parts, electric parts, electronic parts, household goods, and the like. Among them, it is known that a polyamide resin to which an inorganic reinforcing material typified by glass fiber is added has greatly improved rigidity, strength, and heat resistance, and in particular, rigidity is improved in proportion to the amount added. However, when an inorganic reinforcing material such as glass fiber is added in a large amount of 50% by mass or more and 70% by mass or less for the purpose of improving rigidity and strength in the polyamide resin, the appearance of the molded product is extremely deteriorated and the commercial value is remarkably impaired. . Thus, as a method for improving the appearance of a molded product, it has been proposed to add an amorphous resin to a crystalline polyamide resin (see, for example, Patent Documents 1 to 3).

  Further, a method is known in which a semi-aromatic polyamide resin (MXD-6) is highly filled with nylon 66, glass fiber, and mica to increase strength and rigidity (for example, see Patent Document 4).

  Further, as a material capable of improving the surface appearance and mechanical properties of a molded product, a polyamide composition comprising a polycapramide resin, a semi-aromatic amorphous polyamide resin 6T / 6I, and an inorganic reinforcing material has been proposed ( For example, see Patent Document 5).

Japanese Patent Laid-Open No. 2-140265 Japanese Patent Laid-Open No. 3-009952 JP-A-3-269056 JP-A-1-263151 JP 2000-154316 A

  However, the techniques disclosed in Patent Documents 1 to 3 have room for further improvement in terms of both fluidity, appearance of the molded product, and rigidity at the time of water absorption. In the technique disclosed in Patent Document 4, it is necessary to raise the mold temperature at the time of molding to as high as 135 ° C., and even when it is raised to a high temperature, a good molded product appearance may not be obtained. In the technique disclosed in Patent Document 5, although the surface appearance and the rigidity under normal use conditions are improved, there is room for further improvement in terms of the compatibility between the fluidity, the appearance of the molded product, and the rigidity at the time of water absorption. It was.

  This invention is made | formed in view of the said situation, Comprising: The polyamide composition which is excellent in the rigidity and fluidity | liquidity at the time of water absorption, and can form the molded article excellent in the surface external appearance property is provided. In addition, the present invention provides a molded article containing the polyamide composition and having excellent surface appearance.

That is, the present invention includes the following aspects.
The polyamide composition according to the first aspect of the present invention is a polyamide composition containing (A) an aliphatic polyamide, and (B) a semi-aromatic polyamide containing a dicarboxylic acid unit and a diamine unit, (A) 50 mass parts or more and 99 mass parts or less of said (A) aliphatic polyamide with respect to the total mass of 100 mass parts of aliphatic polyamide and said (B) semi-aromatic polyamide, and said (B) semi-aromatic 1 to 50 parts by mass of an aliphatic polyamide, and the (A) aliphatic polyamide is selected from the group consisting of lactam units having 4 to 14 carbon atoms and aminocarboxylic acid units having 4 to 14 carbon atoms. The (B) semi-aromatic polyamide contains at least one kind, and the total dicarboxylic acid unit constituting the (B) semi-aromatic polyamide contains 75 mol% or less of isophthalic acid units. And (B) the total diamine unit constituting the semi-aromatic polyamide contains 50 mol% or more of diamine units having 4 to 10 carbon atoms, and the weight average molecular weight Mw of the polyamide composition is 15000 to 35000. It is as follows.

  The polyamide composition according to the first aspect further contains (C) an inorganic filler, and the content of the (C) inorganic filler is based on 100 parts by mass of the total polyamide in the polyamide composition. 5 mass parts or more and 250 mass parts or less may be sufficient.

  In the polyamide composition according to the first aspect, the shape of the (C) inorganic filler may be at least one of a needle shape and a plate shape.

  In the polyamide composition according to the first aspect, among the total polyamides in the polyamide composition, the total content of polyamides having a number average molecular weight Mn of 500 or more and 2000 or less is the total mass of the polyamide in the polyamide composition. However, it may be 2.5% by mass or more and less than 4.0% by mass.

  In the polyamide composition according to the first aspect, the (A) aliphatic polyamide may be polyamide 6.

  In the polyamide composition according to the first aspect, the (B) semi-aromatic polyamide may be polyamide 6I.

  In the polyamide composition according to the first aspect, a molecular weight distribution Mw / Mn of the polyamide composition may be 2.4 or less.

  In the polyamide composition according to the first aspect, a molecular weight distribution Mw / Mn of the polyamide composition may be 2.2 or less.

  In the polyamide composition according to the first aspect, the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide may be 10,000 or more and 25,000 or less.

  In the polyamide composition according to the first aspect, the molecular weight distribution Mw (B) / Mn (B) of the (B) semi-aromatic polyamide may be 2.4 or less.

  In the polyamide composition according to the first aspect, the difference between the weight average molecular weight Mw (A) of the (A) aliphatic polyamide and the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide {Mw (A ) -Mw (B)} may be less than 10,000.

  In the polyamide composition according to the first aspect, the difference between the weight average molecular weight Mw (A) of the (A) aliphatic polyamide and the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide {Mw (A ) -Mw (B)} may be 10,000 or more and 20,000 or less.

  The polyamide composition according to the first aspect may further contain at least one selected from the group consisting of (H) metal phosphite and metal hypophosphite.

  The polyamide composition according to the first aspect may further contain (I) a phosphite compound.

  The molded product according to the second aspect of the present invention is formed by molding the polyamide composition according to the first aspect, and has a surface gloss value of 80 or more.

  The polyamide composition of the above aspect can form a molded article having excellent rigidity and fluidity at the time of water absorption and excellent surface appearance. Moreover, the molded article of the said aspect contains the said polyamide composition, and is excellent in surface appearance property.

  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 thereof.

  In the present specification, “polyamide” means a polymer having an amide (—NHCO—) group in the main chain.

≪Polyamide composition≫
The polyamide composition of the present embodiment contains (A) an aliphatic polyamide and (B) a semi-aromatic polyamide containing a dicarboxylic acid unit and a diamine unit.

  Moreover, the polyamide composition of the present embodiment is 50 parts by mass or more and 99 parts by mass or less of (A) aliphatic polyamide with respect to 100 parts by mass of the total mass of (A) aliphatic polyamide and (B) semi-aromatic polyamide. And (B) 1 to 50 parts by mass of semi-aromatic polyamide.

  In the polyamide composition of the present embodiment, (A) the aliphatic polyamide comprises at least one selected from the group consisting of a lactam unit having 4 to 14 carbon atoms and an aminocarboxylic acid unit having 4 to 14 carbon atoms. Including.

  Further, in the polyamide composition of the present embodiment, (B) the semi-aromatic polyamide contains 75 mol% or more of isophthalic acid units in the total dicarboxylic acid units constituting the (B) semi-aromatic polyamide, and (B) 50 mol% or more of diamine units having 4 to 10 carbon atoms are contained in all diamine units constituting the semi-aromatic polyamide.

  Moreover, the molecular weight, melting | fusing point Tm2, and crystallization enthalpy (DELTA) H of the polyamide composition of this embodiment can be set as the following structure, and can be specifically measured by the method as described in the Example mentioned later.

<Weight average molecule (Mw) of polyamide composition>
As an index of the molecular weight of the polyamide composition, a weight average molecule (Mw) can be used.
The weight average molecule (Mw) of the polyamide composition is 15000 or more and 35000 or less, preferably 16000 or more and 33000 or less, more preferably 17000 or more and 32000 or less, further preferably 18000 or more and 31000 or less, and particularly preferably 20000 or more and 30000 or less.
When the weight average molecule (Mw) of the polyamide composition is in the above range, a polyamide having excellent mechanical properties, particularly water absorption rigidity, heat rigidity, fluidity, and the like can be obtained. Moreover, the molded product obtained from the polyamide composition containing the component represented by (C) inorganic filler becomes more excellent in surface appearance.
Examples of a method for controlling the Mw of the polyamide composition within the above range include using (A) a polyamide and (B) a semi-aromatic polyamide having a Mw within the range described below.
In addition, the measurement of Mw (weight average molecular weight) can be measured using GPC (gel permeation chromatography) as described in the following Example.

<Total content of number average molecular weight Mn of 500 or more and 2000 or less among total polyamide in polyamide composition>
Among the total polyamide in the polyamide composition, the total content of those having a number average molecular weight Mn of 500 or more and 2000 or less is 1.5% by mass or more and 4.0% by mass with respect to the total mass of the polyamide in the polyamide composition. % Is preferably 2.0% by mass or more and less than 4.0% by mass, more preferably 2.0% by mass or more and less than 3.5% by mass, more preferably 2.3% by mass or more and less than 3.5% by mass. Particularly preferred is 2.5% by mass or more and less than 3.5% by mass.
Among the total polyamides in the polyamide composition, the number average molecular weight Mn is not less than 500 and not more than 2000, and the total content is not less than the above lower limit value, so that the fluidity is excellent and (C) the inorganic filler is representative. There exists a tendency which can make the molded article obtained from the polyamide composition containing the component made more excellent in surface appearance property. Moreover, it exists in the tendency which can suppress more effectively gas generation at the time of shaping | molding because total content is less than the said upper limit.
Among the total polyamides in the polyamide composition, as a method for controlling the total content of those having a number average molecular weight Mn of 500 or more and 2000 or less within the above range, for example, the molecular weight of (B) semi-aromatic polyamide is adjusted. Methods and the like. At this time, the weight average molecular weight (Mw (B)) of the (B) semi-aromatic polyamide is preferably 10,000 to 25,000.

In addition, the total content of those having a number average molecular weight Mn of 500 or more and 2000 or less among the total polyamide in the polyamide composition can be determined from the elution curve under the measurement conditions in Examples described later using GPC. .
Further, in the case of GPC measurement, in the composition containing (A) aliphatic polyamide and (B) semi-aromatic polyamide, when other components that are soluble in a solvent for dissolving the polyamide are contained, GPC measurement can be performed after extracting and removing other components using a solvent in which polyamide is insoluble but other components are soluble. Further, the inorganic filler (C) that is insoluble in the solvent for dissolving the polyamide can be dissolved in the solvent for dissolving the polyamide composition, and then filtered to remove insoluble matters, and then GPC measurement can be performed. .

<Molecular weight distribution of polyamide composition>
The molecular weight distribution of the polyamide composition of the present embodiment uses weight average molecular weight (Mw) / number average molecular weight (Mn) as an index.
The lower limit of the weight average molecular weight (Mw) / number average molecular weight (Mn) of the polyamide composition of the present embodiment is preferably 1.0, more preferably 1.7, still more preferably 1.8, and 1.9 Particularly preferred.
On the other hand, the upper limit of Mw / Mn of the polyamide composition of the present embodiment is preferably 2.4, more preferably 2.3, and even more preferably 2.2.
That is, Mw / Mn of the polyamide composition of the present embodiment is 2.4 or less, preferably 1.0 or more and 2.4 or less, more preferably 1.7 or more and 2.3 or less, and 1.8 or more and 2. 3 or less is more preferable, and 1.9 or more and 2.1 or less is particularly preferable.
When Mw / Mn is in the above range, a polyamide composition excellent in fluidity tends to be obtained. Moreover, the molded product obtained from the polyamide composition containing the component represented by (C) inorganic filler tends to be more excellent in surface appearance.

As a method for controlling the weight average molecular weight (Mw) / number average molecular weight (Mn) of the polyamide composition within the above range, (B) weight average molecular weight (Mw (B)) / number average molecular weight of semi-aromatic polyamide ( Examples thereof include a method of setting Mn (B)) to a range described later.
When the aromatic compound unit is contained in the molecular structure of the polyamide composition, the molecular weight distribution (Mw / Mn) tends to increase as the molecular weight increases. When the molecular weight distribution is within the above range, the proportion of polyamide molecules having a three-dimensional structure of the molecule can be lowered, and the three-dimensional structure of the molecule can be more suitably prevented during high-temperature processing, and the fluidity can be reduced. It can be kept better. Thereby, it exists in the tendency which can make the surface external appearance of the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler more favorable.
As the weight average molecular weight (Mw) / number average molecular weight (Mn) of the polyamide composition, the weight average molecular weight (Mw) and number average molecular weight (Mn) obtained by using GPC are used, as shown in Examples described later. And can be calculated.

<Melting point Tm2 of polyamide composition>
The melting point Tm2 of the polyamide composition is preferably 200 ° C or higher, more preferably 210 ° C or higher and 270 ° C or lower, further preferably 210 ° C or higher and 260 ° C or lower, particularly preferably 210 ° C or higher and 250 ° C or lower, and 210 ° C or higher and 230 ° C or lower. Is most preferred.
When the melting point Tm2 of the polyamide composition is not less than the above lower limit value, it tends to be able to obtain a polyamide composition that is superior in rigidity (high temperature rigidity) under high temperature use.
On the other hand, when the melting point Tm2 of the polyamide composition is not more than the above upper limit value, the thermal decomposition of the polyamide composition in the melt processing such as extrusion and molding tends to be further suppressed.

<Crystallization enthalpy ΔH of polyamide composition>
The crystallization enthalpy ΔH of the polyamide composition is preferably 8 J / g or more, more preferably 10 J / g or more, further preferably 12 J / g or more, from the viewpoints of mechanical properties, particularly water absorption rigidity and thermal rigidity. g or more is particularly preferable. On the other hand, the upper limit value of the crystallization enthalpy ΔH is not particularly limited, and the higher the better.
Examples of the method of controlling the crystallization enthalpy ΔH of the polyamide composition within the above range include a method of controlling the contents of (A) aliphatic polyamide and (B) semi-aromatic polyamide within the above-described range. .
Examples of the measuring device for the melting point Tm2 and the crystallization enthalpy ΔH of the polyamide composition include Diamond-DSC manufactured by PERKIN-ELMER.

<The crystallization peak temperature Tc obtained when the polyamide composition is cooled at 20 ° C./min>
The crystallization peak temperature Tc (° C) obtained when the polyamide composition is cooled at 20 ° C / min is preferably from 160 ° C to 220 ° C, more preferably from 160 ° C to 210 ° C, and from 160 ° C to 200 ° C. More preferably, 165 to 190 ° C is particularly preferable, and 165 to 180 ° C is most preferable.
When the crystallization peak temperature Tc (° C.) of the polyamide composition is equal to or higher than the above lower limit value, a polyamide composition that is more excellent in releasability during molding can be obtained.
On the other hand, when the crystallization peak temperature Tc (° C.) of the polyamide composition is not more than the above upper limit, (C) the surface appearance of a molded product obtained from the polyamide composition containing a component represented by an inorganic filler. Is better.
The melting point crystallization peak temperature Tc of the polyamide composition of the present embodiment can be measured according to JIS-K7121 by the method described in the examples described later.
Examples of the measuring device for the crystallization peak temperature Tc include Diamond-DSC manufactured by PERKIN-ELMER.
Examples of the method of controlling the crystallization peak temperature Tc of the polyamide within the above range include a method of controlling the contents of (A) aliphatic polyamide and (B) semi-aromatic polyamide within the above-described ranges.

The polyamide composition of this embodiment can form a molded product having excellent rigidity and fluidity at the time of water absorption and excellent surface appearance by having the above configuration.
Hereinafter, the detail of each structural component of the polyamide composition of this embodiment is demonstrated.

<(A) Aliphatic polyamide>
The (A) aliphatic polyamide contained in the polyamide composition of the present embodiment preferably contains at least one selected from the group consisting of (Aa) lactam units and aminocarboxylic acid units. That is, (A) aliphatic polyamide is derived from at least one selected from the group consisting of lactams having 4 to 14 carbon atoms and aminocarboxylic acids having 4 to 14 carbon atoms.
As used herein, “lactam unit” and “aminocarboxylic acid unit” refer to a lactam and an aminocarboxylic acid that are combined (condensed).

Examples of such (A) aliphatic polyamides include, but are not limited to, polyamides obtained by ring-opening polymerization of lactams, polyamides obtained by self-condensation of ω-aminocarboxylic acid, and these And the like.
(A) The aliphatic polyamide includes at least one selected from the group consisting of lactams having 4 to 14 carbon atoms and aminocarboxylic acids having 4 to 14 carbon atoms, and other monomers such as diamines and dicarboxylic acids. The copolymer may be used.

(A) The total content of lactam units and aminocarboxylic units in the aliphatic polyamide is preferably 50 mol% or more and 100 mol% or less, and 55 mol% or more with respect to all structural units of the (A) aliphatic polyamide. 100 mol% or less is more preferable, and 60 mol% or more and 100% or less is more preferable.
(A) When the total content of the lactam unit and aminocarboxylic unit in the aliphatic polyamide is in the above range, a polyamide composition excellent in fluidity, surface appearance of the molded product and the like tends to be obtained.
In the present invention, the ratio of the predetermined monomer units constituting the (A) aliphatic polyamide can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[(Aa) At least one selected from the group consisting of lactam units and aminocarboxylic acid units]
The lactam constituting the lactam unit is a lactam having 4 to 14 carbon atoms, and a lactam having 6 to 12 carbon atoms is preferable.
The aminocarboxylic acid constituting the aminocarboxylic acid unit is an aminocarboxylic acid having 4 to 14 carbon atoms, preferably an aminocarboxylic acid having 6 to 12 carbon atoms.
Examples of the lactam constituting the lactam unit include, but are not limited to, butyrolactam, pivalolactam, ε-caprolactam, caprilactam, enantolactam, undecanolactam, laurolactam (dodecanolactam), and the like. It is done.
Especially, as a lactam which comprises a lactam unit, (epsilon) -caprolactam or laurolactam is preferable, and (epsilon) -caprolactam is more preferable. By including such a lactam, the toughness of a molded product obtained from the polyamide composition tends to be more excellent.
The aminocarboxylic acid constituting the aminocarboxylic acid unit is not limited to the following, and examples thereof include ω-aminocarboxylic acid and α, ω-amino acid which are compounds in which a lactam is ring-opened.
As the aminocarboxylic acid constituting the aminocarboxylic acid unit, a linear or branched saturated aliphatic carboxylic acid having 4 to 14 carbon atoms and substituted at the ω position with an amino group is preferable. Examples of such aminocarboxylic acids include, but are not limited to, 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like. Examples of the aminocarboxylic acid include paraaminomethylbenzoic acid.
These (Aa) lactams and aminocarboxylic acids constituting at least one selected from the group consisting of lactam units and aminocarboxylic acid units may be used alone or in combination of two or more. You may use in combination.
Especially, as (A) aliphatic polyamide contained in the polyamide composition of this embodiment, polyamide 6 (PA6) is preferable from a viewpoint of mechanical characteristics, heat resistance, moldability, and toughness.

The content of the (A) aliphatic polyamide in the polyamide composition of the present embodiment is 50 parts by mass or more and 99 parts by mass with respect to 100 parts by mass of the total mass of (A) the aliphatic polyamide and (B) the semi-aromatic polyamide. Part or less, 55 mass% or more and 95 mass% or less are preferable, 57.5 mass% or more and 90 mass% or less are more preferable, and 60 mass% or more and 85 mass% or less are more preferable.
(A) By making content of aliphatic polyamide into the said range, the polyamide composition which is excellent by mechanical properties, especially water absorption rigidity, thermal rigidity, fluidity, etc. is obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.

<(B) Semi-aromatic polyamide>
The (B) semi-aromatic polyamide contained in the polyamide composition of the present embodiment is a polyamide containing a diamine unit and a dicarboxylic acid unit.
The (B) semi-aromatic polyamide comprises (B-a) a dicarboxylic acid unit containing 75 mol% or more of an isophthalic acid unit with respect to the total dicarboxylic acid unit of the (B) semi-aromatic polyamide; It is preferable that it is a polyamide containing the (Bb) diamine unit containing 50 mol% or more of diamine units having 4 to 10 carbon atoms with respect to all diamine units of the polyamide.
At this time, the total content of the isophthalic acid unit and the diamine unit having 4 to 10 carbon atoms in the (B) semi-aromatic polyamide is 80 mol relative to the total structural unit of the (B) semi-aromatic polyamide. % To 100 mol% is preferable, 90 mol% to 100 mol% is more preferable, and 100 mol% is more preferable.
In the present invention, the ratio of the predetermined monomer unit constituting (B) the semi-aromatic polyamide can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[(B-a) dicarboxylic acid unit]
(Ba) The dicarboxylic acid unit is not particularly limited, and examples thereof include an aromatic dicarboxylic acid unit, an aliphatic dicarboxylic acid unit, and an alicyclic dicarboxylic acid unit.
Among them, the (Ba) dicarboxylic acid unit contains 75 mol% or more of isophthalic acid and 80 mol% or more and 100 mol% or less of isophthalic acid with respect to the total number of moles of (Ba) dicarboxylic acid. Is preferable, more preferably 90 mol% to 100 mol%, and even more preferably 100 mol%.
(Ba) When the ratio of the isophthalic acid unit in the dicarboxylic acid unit is not less than the above lower limit, a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, and the like can be obtained. There is a tendency. Moreover, it exists in the tendency for the surface appearance property to be more excellent about the molded article obtained from a polyamide composition.

(Aromatic dicarboxylic acid unit)
The aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit other than the isophthalic acid unit is not limited to the following, but examples thereof include dicarboxylic acids having an aromatic group such as a phenyl group and a naphthyl group. The aromatic group of the aromatic dicarboxylic acid may be unsubstituted or may have a substituent.
The substituent is not particularly limited, and for example, an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, an arylalkyl group having 7 to 10 carbon atoms, a halogen group, and 1 carbon atom. Examples include silyl groups, sulfonic acid groups and salts thereof (sodium salts, etc.) of 6 or less.
Examples of the alkyl group having 1 to 4 carbon atoms include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Etc.
Examples of the aryl group having 6 to 10 carbon atoms include, but are not limited to, phenyl group, tolyl group, xylyl group, naphthyl group, and the like.
Examples of the arylalkyl group having 7 to 10 carbon atoms include, but are not limited to, a benzyl group.
Examples of the halogen group include, but are not limited to, a fluoro group, a chloro group, a bromo group, and an iodo group.
Examples of the silyl group having 1 to 6 carbon atoms include, but are not limited to, a trimethylsilyl group and a tert-butyldimethylsilyl group.
Especially, as aromatic dicarboxylic acid which comprises aromatic dicarboxylic acid units other than an isophthalic acid unit, C8-C20 aromatic dicarboxylic acid substituted by the unsubstituted or predetermined substituent is preferable.

Specific examples of the aromatic dicarboxylic acid having 8 to 20 carbon atoms that are unsubstituted or substituted with a predetermined substituent include, but are not limited to, for example, terephthalic acid, naphthalenedicarboxylic acid, 2-chloro Examples include terephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid.
The aromatic dicarboxylic acid which comprises an aromatic dicarboxylic acid unit may be used individually by 1 type, and may be used in combination of 2 or more type.

(Aliphatic dicarboxylic acid unit)
Examples of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit include linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms.
Examples of the linear saturated aliphatic dicarboxylic acid having 3 to 20 carbon atoms include, but are not limited to, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid. , Sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid, diglycolic acid and the like.
Examples of the branched saturated aliphatic dicarboxylic acid having 3 to 20 carbon atoms include, but are not limited to, dimethyl malonic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl glutaric acid, Examples include 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, and the like.

(Alicyclic dicarboxylic acid unit)
The alicyclic dicarboxylic acid constituting the alicyclic dicarboxylic acid unit (hereinafter sometimes referred to as “alicyclic dicarboxylic acid unit”) is not limited to the following, but for example, an alicyclic structure Examples thereof include alicyclic dicarboxylic acids having 3 to 10 carbon atoms. Among these, as the alicyclic dicarboxylic acid, alicyclic dicarboxylic acids having 5 to 10 carbon atoms in the alicyclic structure are preferable.
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. It is done. Among these, 1,4-cyclohexanedicarboxylic acid is preferable as the alicyclic dicarboxylic acid.
In addition, the alicyclic dicarboxylic acid which comprises an alicyclic dicarboxylic acid unit may be used individually by 1 type, and may be used in combination of 2 or more types.

  The alicyclic group of the alicyclic dicarboxylic acid may be unsubstituted or may have a substituent. Examples of the substituent include an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms are the same as those exemplified in the above “aromatic dicarboxylic acid unit”.

The dicarboxylic acid unit other than the isophthalic acid unit preferably includes an aromatic dicarboxylic acid unit, and more preferably includes an aromatic dicarboxylic acid having 6 or more carbon atoms.
By using such a dicarboxylic acid, there is a tendency to obtain a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, and the like. Moreover, it exists in the tendency for the surface appearance property to be more excellent about the molded article obtained from a polyamide composition.

(B) In the semi-aromatic polyamide, (B-a) the dicarboxylic acid constituting the dicarboxylic acid unit is not limited to the compounds described as the dicarboxylic acid, and is a compound equivalent to the dicarboxylic acid. Also good.
As used herein, “a compound equivalent to a dicarboxylic acid” means a compound that can have a dicarboxylic acid structure similar to the dicarboxylic acid structure derived from the dicarboxylic acid. Examples of such compounds include, but are not limited to, dicarboxylic acid anhydrides, dicarboxylic acid halides, and the like.

In addition, (B) the semi-aromatic polyamide may further include a unit derived from a trivalent or higher polyvalent carboxylic acid, if necessary, as long as the effects of the polyamide composition of the present embodiment are not impaired.
Examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid, trimesic acid, pyromellitic acid, and the like. These trivalent or higher polyvalent carboxylic acids may be used alone or in combination of two or more.

[(B-b) diamine unit]
(B) The (Bb) diamine unit constituting the semi-aromatic polyamide is not particularly limited, and examples thereof include an aromatic diamine unit, an aliphatic diamine unit, and an alicyclic diamine unit. Among these, the (Bb) diamine unit constituting the (B) semi-aromatic polyamide preferably includes a diamine unit having 4 to 10 carbon atoms, and includes a diamine unit having 6 to 10 carbon atoms. More preferred.

  Further, at this time, the (Bb) diamine unit contains 50 mol% or more of diamine units having 4 to 10 carbon atoms, and 4 to 10 carbon atoms, based on the total number of moles of (Bb) diamine units. The following diamine units are preferably contained in an amount of 60 mol% to 100 mol%, more preferably 70 mol% to 100 mol%, further preferably 80 mol% to 100 mol%, and more preferably 90% mol%. The content is particularly preferably 100 mol% or less and most preferably 100 mol%.

(Aliphatic diamine unit)
Examples of the aliphatic diamine constituting the aliphatic diamine unit include linear saturated aliphatic diamines having 4 to 20 carbon atoms.
Examples of the linear saturated aliphatic diamine having 4 to 20 carbon atoms include, but are not limited to, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, Examples include octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and tridecamethylene diamine.

(Alicyclic diamine unit)
The alicyclic diamine constituting the alicyclic diamine unit (hereinafter sometimes referred to as “alicyclic diamine”) is not limited to the following, but includes, for example, 1,4-cyclohexanediamine, 1 , 3-cyclohexanediamine, 1,3-cyclopentanediamine and the like.

(Aromatic diamine unit)
The aromatic diamine constituting the aromatic diamine unit is not limited to the following as long as it is a diamine containing an aromatic. Specific examples of the aromatic diamine include metaxylylenediamine.

  In addition, the diamine which comprises each of these diamine units may be used individually by 1 type, and may be used in combination of 2 or more types.

Among them, the (Bb) diamine unit is preferably an aliphatic diamine unit, more preferably a linear saturated aliphatic diamine unit having 4 to 10 carbon atoms, and a linear saturated fat having 6 to 10 carbon atoms. A group diamine unit is more preferable, and a hexamethylenediamine unit is particularly preferable.
By using such a diamine, there is a tendency to obtain a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, and the like. Moreover, it exists in the tendency for the surface appearance property to be more excellent about the molded article obtained from a polyamide composition.

  As the (B) semi-aromatic polyamide contained in the polyamide composition of the present embodiment, polyamide 6I (polyhexamethylene isophthalamide), polyamide 9I or polyamide 10I is preferable, and polyamide 6I is more preferable.

The content of (B) semi-aromatic polyamide in the polyamide composition of the present embodiment is 1 part by mass or more and 50 parts by mass with respect to 100 parts by mass of the total mass of (A) aliphatic polyamide and (B) semi-aromatic polyamide. 5 parts by mass or more and 45 parts by mass or less are preferable, 10 parts by mass or more and 42.5 parts by mass or less are more preferable, and 15 parts by mass or more and 40 parts by mass or less are more preferable.
(B) By making content of a semi-aromatic polyamide into the said range, the polyamide composition which is excellent by mechanical properties, especially water-absorbing rigidity, thermal rigidity, fluidity, etc. is obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.

<End sealant>
The ends of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained in the polyamide composition of the present embodiment may be end-capped with a known end-capping agent.
Such an end-capping agent can be used as a molecular weight regulator in the production of polyamide from at least one selected from the group consisting of the dicarboxylic acid and the diamine or the lactam and the aminocarboxylic acid. Can be added.

Examples of the end capping agent include, but are not limited to, monocarboxylic acids, monoamines, acid anhydrides (phthalic anhydride, etc.), monoisocyanates, monoacid halides, monoesters, monoalcohols. Etc.
Especially, as a terminal blocker, monocarboxylic acid or monoamine is preferable. When the terminal of the polyamide is blocked with a terminal blocking agent, the thermal stability of the molded product obtained from the polyamide composition tends to be more excellent.
Only one type of end capping agent may be used alone, or two or more types may be used in combination.

The monocarboxylic acid that can be used as the end-capping agent may be any one having reactivity with an amino group that may be present at the end of the polyamide. Examples of monocarboxylic acids include, but are not limited to, aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids.
Examples of the aliphatic monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid and the like. Can be mentioned.
Examples of the alicyclic monocarboxylic acid include cyclohexane carboxylic acid.
Examples of the aromatic monocarboxylic acid include benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid.
These monocarboxylic acids may be used alone or in combination of two or more.

The monoamine that can be used as the end-capping agent may be any one that has reactivity with a carboxyl group that may be present at the end of the polyamide. Examples of monoamines include, but are not limited to, aliphatic monoamines, alicyclic monoamines, and aromatic monoamines.
Examples of the aliphatic monoamine include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine and the like.
Examples of the alicyclic monoamine include cyclohexylamine and dicyclohexylamine.
Examples of the aromatic monoamine include aniline, toluidine, diphenylamine, naphthylamine and the like.
These monoamines may be used alone or in combination of two or more.

  A polyamide composition containing a polyamide end-capped with a terminal capping agent tends to be more excellent in heat resistance, fluidity, toughness, low water absorption, and rigidity.

<Production method of (A) aliphatic polyamide and (B) semi-aromatic polyamide>
When the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained in the polyamide composition of this embodiment is produced, the addition amount of dicarboxylic acid and the addition amount of diamine are close to the same molar amount. It is preferable that Considering the amount of diamine escaped from the reaction system during the polymerization reaction in terms of molar ratio, the molar amount of the diamine is preferably 0.9 or more and 1.2 or less with respect to the molar amount 1 of the entire dicarboxylic acid. 0.95 or more and 1.1 or less is more preferable, and 0.98 or more and 1.05 or less is more preferable.

The method for producing polyamide is not limited to the following, but includes, for example, the following polymerization step (1) or (2).
(1) A step of polymerizing a combination of a dicarboxylic acid constituting a dicarboxylic acid unit and a diamine constituting a diamine unit to obtain a polymer.
(2) A step of obtaining a polymer by polymerizing at least one selected from the group consisting of a lactam constituting a lactam unit and an aminocarboxylic acid constituting an aminocarboxylic acid unit.

  Moreover, as a manufacturing method of polyamide, it is preferable to further include the raising process which raises the polymerization degree of polyamide after the said polymerization process. Moreover, you may include the sealing process which seals the terminal of the obtained polymer with a terminal blocker after the said superposition | polymerization process and the said raise process as needed.

Specific methods for producing the polyamide include various methods as exemplified in the following 1) to 4).
1) One or more aqueous solutions or water suspensions selected from the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams, and aminocarboxylic acids are heated and polymerized while maintaining the molten state. (Hereinafter sometimes referred to as “hot melt polymerization method”).
2) A method of increasing the degree of polymerization of the polyamide obtained by the hot melt polymerization method while maintaining the solid state at a temperature below the melting point (hereinafter sometimes referred to as “hot melt polymerization / solid phase polymerization method”).
3) A method of polymerizing one or more selected from the group consisting of a dicarboxylic acid-diamine salt, a mixture of a dicarboxylic acid and a diamine, a lactam, and an aminocarboxylic acid while maintaining a solid state (hereinafter referred to as “solid phase weight”). Sometimes referred to as “legal”).
4) A method of polymerizing using a dicarboxylic acid halide component equivalent to dicarboxylic acid and a diamine component (hereinafter sometimes referred to as “solution method”).

Among these, as a specific method for producing polyamide, a production method including a hot melt polymerization method is preferable. Moreover, when manufacturing polyamide by a hot melt polymerization method, it is preferable to maintain a molten state until superposition | polymerization is complete | finished. In order to maintain the molten state, it is necessary to produce it under polymerization conditions suitable for the polyamide composition. Examples of the polymerization conditions include the following conditions. First, the polymerization pressure in the hot melt polymerization method is controlled to 14 kg / cm ² or more and 25 kg / cm ² or less (gauge pressure), and heating is continued. Next, the pressure is lowered while taking 30 minutes or more until the pressure in the tank reaches atmospheric pressure (gauge pressure is 0 kg / cm ² ).

In the method for producing polyamide, the polymerization form is not particularly limited, and may be a batch type or a continuous type.
The polymerization apparatus used for producing the polyamide is not particularly limited, and a known apparatus can be used. Specific examples of the polymerization apparatus include an autoclave reactor, a tumbler reactor, an extruder reactor (kneader, etc.), and the like.

Hereinafter, as a method for producing polyamide, a method for producing polyamide by a batch-type hot melt polymerization method will be specifically described, but the method for producing polyamide is not limited thereto.
First, a raw material component of polyamide (a combination of dicarboxylic acid and diamine, and if necessary, at least one selected from the group consisting of lactam and aminocarboxylic acid) is contained in an amount of about 40% by mass to 60% by mass. Prepare an aqueous solution. Next, the temperature of the aqueous solution is 110 ° C. or higher and 180 ° C. or lower, and In a concentration tank operated at a pressure of about 0.035 MPa to 0.6 MPa (gauge pressure), the solution is concentrated to about 65% by mass to 90% by mass to obtain a concentrated solution.
Next, the obtained concentrated solution is transferred to an autoclave, and heating is continued until the pressure in the autoclave reaches about 1.2 MPa to 2.2 MPa (gauge pressure).
Next, in the autoclave, the pressure is maintained at about 1.2 MPa or more and 2.2 MPa or less (gauge pressure) while removing at least one of water and gas components. Next, when the temperature reaches about 220 ° C. or higher and 260 ° C. or lower, the pressure is reduced to atmospheric pressure (gauge pressure is 0 MPa). By reducing the pressure in the autoclave to atmospheric pressure and then reducing the pressure as necessary, by-product water can be effectively removed.
Next, the autoclave is pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave as a strand. The extruded strand is cooled and cut to obtain polyamide pellets.

<Polymer end of polyamide>
The polymer terminal of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained in the polyamide composition of the present embodiment is not particularly limited, but is classified and defined in the following 1) to 4). can do.
That is, 1) amino terminal, 2) carboxyl terminal, 3) terminal by a sealant, and 4) other terminal.
1) The amino terminal is a polymer terminal having an amino group (—NH ₂ group) and is derived from a diamine unit.
2) The carboxyl end is a polymer end having a carboxyl group (—COOH group) and is derived from a dicarboxylic acid.
3) The terminal by a sealing agent is a terminal formed when a sealing agent is added at the time of superposition | polymerization. Examples of the sealing agent include the above-described end sealing agents.
4) The other terminal is a polymer terminal not classified in the above 1) to 3). Specific examples of the other terminal include a terminal generated by deammonia reaction at the amino terminal, a terminal generated by decarboxylation from the carboxyl terminal, and the like.

<Characteristics of polyamide>
[(A) Characteristics of aliphatic polyamide]
(A) The molecular weight of the aliphatic polyamide can have the following constitution, and specifically can be measured by the method shown below.

((A) Weight average molecular weight Mw (A) of aliphatic polyamide)
(A) The weight average molecular weight can be used as an index of the molecular weight of the aliphatic polyamide. (A) The weight average molecular weight (Mw (A)) of the aliphatic polyamide is preferably from 10,000 to 50,000, more preferably from 15,000 to 45,000, further preferably from 18,000 to 30,000, and particularly preferably from 18,000 to 25,000.
When Mw (A) is in the above range, a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, and the like tends to be obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.
In addition, the measurement of the weight average molecular weight (Mw (A)) of (A) aliphatic polyamide can be measured using GPC.

((A) Molecular weight distribution of aliphatic polyamide)
The molecular weight distribution of (A) aliphatic polyamide uses (A) weight average molecular weight of aliphatic polyamide (Mw (A)) / (A) number average molecular weight of aliphatic polyamide (Mn (A)) as an index.
Mw (A) / Mn (A) is 1.0 or more, preferably 1.8 or more and 2.4 or less, and more preferably 1.9 or more and 2.2 or less.
When Mw (A) / Mn (A) is in the above range, a polyamide composition having excellent fluidity and the like can be obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.

Examples of the method for controlling Mw (A) / Mn (A) within the above range include the methods shown in 1) or 2) below.
1) A method in which a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite is added as an additive during hot melt polymerization of polyamide.
2) A method for controlling polymerization conditions such as heating conditions and reduced pressure conditions in addition to the above method 1).

  In addition, the molecular weight distribution of (A) aliphatic polyamide is measured by (A) weight average molecular weight of aliphatic polyamide (Mw (A)) / (A) number average molecular weight of aliphatic polyamide (Mn (A)), It can be calculated using Mw (A) and Mn (A) obtained using GPC.

[(B) Characteristics of semi-aromatic polyamide]
(B) The molecular weight, crystallization enthalpy ΔH, amino terminal amount, and carboxy terminal amount of the semi-aromatic polyamide can have the following constitutions, and can be specifically measured by the method shown below.

((B) Weight average molecular weight Mw (B) of semi-aromatic polyamide)
(B) As an index of the molecular weight of the semi-aromatic polyamide, the weight average molecular weight (Mw (B)) of the (B) semi-aromatic polyamide can be used.
(B) The weight average molecular weight (Mw (B)) of the semi-aromatic polyamide is preferably 10,000 or more and 25,000 or less, more preferably 13,000 or more and 24,000 or less, further preferably 15,000 or more and 23,000 or less, and particularly preferably 18,000 or more and 22,000 or less. 19000 or more and 21000 or less are the most preferable.
(B) When the weight average molecular weight (Mw (B)) of the semi-aromatic polyamide is in the above range, a polyamide composition excellent in mechanical properties, in particular, water absorption rigidity, thermal rigidity, fluidity and the like can be obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.
In addition, the measurement of the weight average molecular weight (Mw (B)) of (B) semi-aromatic polyamide can be measured using GPC.

((B) Molecular weight distribution of semi-aromatic polyamide)
(B) The molecular weight distribution of the semi-aromatic polyamide is based on the weight average molecular weight (Mw (B)) / (B) the number average molecular weight (Mn (B)) of the semi-aromatic polyamide as an index. To do.
Mw (B) / Mn (B) is 2.4 or less, preferably 1.0 or more and 2.4 or less, more preferably 1.7 or more and 2.4 or less, and more preferably 1.8 or more and 2.3 or less. It is preferably 1.9 or more and 2.2 or less, and particularly preferably 1.9 or more and 2.1 or less.
When Mw (B) / Mn (B) is in the above range, a polyamide composition having excellent fluidity and the like can be obtained. Moreover, the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler has a more excellent surface appearance.

Examples of the method for controlling Mw (B) / Mn (B) within the above range include the methods shown in 1) or 2) below.
1) A method in which a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite is added as an additive during hot melt polymerization of polyamide.
2) In addition to the above method 1), the polymerization conditions such as heating conditions and reduced pressure conditions are controlled to complete the polycondensation reaction at as low a temperature as possible and in a short time.

In particular, if the (B) semi-aromatic polyamide is an amorphous polyamide, since it does not have a melting point, the reaction temperature can be lowered, which is desirable.
When the aromatic compound unit is contained in the molecular structure of the polyamide, the molecular weight distribution (Mw / Mn) tends to increase as the molecular weight increases. (B) When the molecular weight distribution (Mw (B) / Mn (B)) of the semi-aromatic polyamide is within the above range, the proportion of polyamide molecules having a three-dimensional molecular structure can be reduced, and high-temperature processing is performed. Sometimes, the three-dimensional structure of molecules can be prevented more suitably, and the fluidity can be kept better. Thereby, the surface external appearance of the molded article obtained from the polyamide composition containing the component represented by (C) inorganic filler can be made more favorable.

  In addition, the measurement of Mw (B) / Mn (B) can be calculated using Mw (B) and Mn (B) obtained using GPC.

((B) Crystallization enthalpy ΔH of semi-aromatic polyamide)
(B) The crystallization enthalpy ΔH of the semi-aromatic polyamide is preferably 15 J / g or less, more preferably 10 J / g or less, more preferably 5 J / g or less, from the viewpoint of mechanical properties, particularly water absorption rigidity and thermal rigidity. Preferably, 0 J / g is particularly preferable.
(B) As a method of controlling the crystallization enthalpy ΔH of the semi-aromatic polyamide within the above range, for example, a method of increasing the ratio of the aromatic monomer to the dicarboxylic acid unit can be mentioned. From this viewpoint, the (B) semi-aromatic polyamide preferably contains 75 mol% or more of isophthalic acid as the (B-a) dicarboxylic acid unit in the total dicarboxylic acid unit constituting the (B) semi-aromatic polyamide. 100 mol% is more preferable.
(B) As a measuring apparatus of crystallization enthalpy (DELTA) H of semi-aromatic polyamide, Diamond-DSC by PERKIN-ELMER is mentioned, for example.

((B) Amino terminal amount of semi-aromatic polyamide)
(B) The amino terminal amount of the semi-aromatic polyamide is 5 μg or more and 100 μg or less, preferably 10 μg or more and 90 μg or less, more preferably 20 μg or more and 80 μg or less, and more preferably 30 μg or more and 70 μg based on 1 g of (B) semi-aromatic polyamide. The following is more preferable, and 40 μg or more and 60 μg or less is particularly preferable.
(B) When the amino terminal amount of the semi-aromatic polyamide is in the above range, a polyamide composition excellent in discoloration to heat and light can be obtained.
The amino terminal amount can be measured by neutralization titration.

((B) carboxyl end amount of semi-aromatic polyamide)
The carboxyl end amount of (B) semi-aromatic polyamide is 50 μg or more and 300 μg or less, preferably 100 μg or more and 280 μg or less, more preferably 150 μg or more and 260 μg or less, and more preferably 180 μg or more and 250 μg with respect to 1 g of (B) semi-aromatic polyamide. The following is more preferable, and 200 μg or more and 240 μg or less is particularly preferable.
(B) When the amount of carboxyl terminals of the semi-aromatic polyamide is in the above range, a polyamide composition having excellent fluidity and the like can be obtained. Moreover, the surface appearance of the molded product obtained from the polyamide composition containing the component represented by (C) inorganic filler becomes more excellent.
The carboxyl end amount can be measured by neutralization titration.

[(A) Difference between weight average molecular weight Mw (A) of aliphatic polyamide and (B) weight average molecular weight Mw (B) of semi-aromatic polyamide {Mw (A) -Mw (B)}]
The difference {Mw (A) -Mw (B)} between the weight average molecular weight Mw (A) of the (A) aliphatic polyamide and the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide shall be less than 10,000. 5000 or less is preferable.
When {Mw (A) -Mw (B)} is less than or less than the above upper limit value, the compatibility of (A) aliphatic polyamide and (B) semi-aromatic polyamide is good. A polyamide composition excellent in surface appearance and hot physical properties after water absorption is obtained.
On the other hand, {Mw (A) -Mw (B)} can be 10,000 or more and 20,000 or less, and preferably 10,000 or more and 15,000 or less.
When {Mw (A) -Mw (B)} is in the above range, a polyamide composition having superior mechanical properties and vibration fatigue properties can be obtained.

[Total amount of amino terminal amount and carboxyl terminal amount of polyamide]
The total amount of the amino terminal amount and the carboxyl terminal amount of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) is from 150 μg to 350 μg, preferably from 160 μg to 300 μg, based on 1 g of the polyamide. 170 μg or more and 280 μg or less is more preferable, 180 μg or more and 270 μg or less is more preferable, and 190 μg or more and 260 μg or less is particularly preferable.
When the total amount of the amino terminal amount and the carboxyl terminal amount of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) is within the above range, a polyamide composition excellent in fluidity and the like can be obtained. Moreover, the surface appearance of the molded product obtained from the polyamide composition containing the component represented by (C) inorganic filler becomes more excellent.

<(C) Inorganic filler>
In addition to the (A) aliphatic polyamide and the (B) semi-aromatic polyamide, the polyamide composition of the present embodiment may further contain (C) an inorganic filler.

  The (C) inorganic filler contained in the polyamide composition of the present embodiment is not particularly limited. For example, glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, Clay, flaky glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, calcium monohydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, Titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, fluorine Of calcium, montmorillonite, swelling fluorine mica, apatite and the like. These inorganic fillers may be used individually by 1 type, and may be used in combination of 2 or more type.

Moreover, it is preferable that the shape of the (C) inorganic filler is at least one of a needle shape and a plate shape.
Examples of the acicular inorganic filler include glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, and wollastonite. Especially, as an acicular inorganic filler, 1 or more types chosen from the group which consists of glass fiber, carbon fiber, and wollastonite are preferable, and it is more preferable that both glass fiber and wollastonite are included.
Examples of the plate-like inorganic filler include kaolin, mica, talc and the like. Among these, the plate-like inorganic filler is preferably at least one selected from the group consisting of mica and talc.

(C) When the inorganic filler is glass fiber or carbon fiber, the number average fiber diameter of the glass fiber or carbon fiber is preferably 3 μm or more and 30 μm or less from the viewpoint of improving the toughness and the surface appearance of the molded product. It is more preferably 20 μm or less, further preferably 3 μm or more and 12 μm or less, particularly preferably 3 μm or more and 9 μm or less, and most preferably 4 μm or more and 6 μm or less.
By setting the number average fiber diameter of glass fibers or carbon fibers to the upper limit value or less, it is possible to obtain a polyamide composition that is more excellent in toughness and surface appearance of a molded product. On the other hand, by setting the number average fiber diameter of glass fibers or carbon fibers to be equal to or greater than the above lower limit value, a polyamide composition having an excellent balance between cost and powder handling surface and physical properties (such as fluidity) can be obtained. Furthermore, by setting the number average fiber diameter of the glass fiber or carbon fiber to 3 μm or more and 9 μm or less, a polyamide composition excellent in vibration fatigue characteristics and slidability can be obtained.

The glass fiber or the carbon fiber may have a perfect cross section or a flat shape. Examples of such a flat cross section include, but are not limited to, a rectangle, an oblong shape close to a rectangle, an ellipse, and a saddle shape with a narrowed central portion in the longitudinal direction.
In the present specification, “flatness” means a value represented by D2 / D1 when the major axis of the fiber cross section is D2 and the minor axis of the fiber cross section is D1. The rate is about 1.)

  Among them, as glass fiber or carbon fiber, from the viewpoint of imparting excellent mechanical strength to the polyamide composition, the number average fiber diameter is 3 μm or more and 30 μm or less, the weight average fiber length is 100 μm or more and 750 μm or less, and Those having an aspect ratio (L / D) of the weight average fiber length (L) to the number average fiber diameter (D) of 10 or more and 100 or less can be suitably used.

Further, from the viewpoint of reducing warpage of the plate-shaped molded article and improving heat resistance, toughness, low water absorption and heat aging resistance, the flatness is preferably 1.5 or more, and 1.5 or more and 10.0. The following is more preferable, 2.5 or more and 10.0 or less are more preferable, and 3.1 or more and 6.0 or less are particularly preferable.
When the flatness is in the above range, crushing can be prevented more effectively during the mixing, kneading, molding and other processing with other components, and the desired effect for the molded product can be obtained more sufficiently.

The thickness of the glass fiber or carbon fiber having a flatness ratio of 1.5 or more is not limited to the following, but the minor axis D1 of the fiber cross section is 0.5 μm or more and 25 μm or less, and the major axis D2 of the fiber cross section is It is preferable that they are 1.25 micrometers or more and 250 micrometers or less.
When the short diameter D1 and the long diameter D2 of the fiber cross section of the glass fiber or carbon fiber having a flatness ratio of 1.5 or more are within the above range, the difficulty of spinning the fiber can be more effectively avoided, and the resin (polyamide) The strength of the molded product can be further improved without reducing the contact area.

  Further, it is more preferable that the glass fiber or carbon fiber short diameter D1 is 3 μm or more and 25 μm or less and the flatness is larger than 3.

  These glass fibers and carbon fibers having a flatness ratio of 1.5 or more include, for example, Japanese Patent Publication No. 3-059019 (Reference Document 1), Japanese Patent Publication No. 4-013300 (Reference Document 2), and Japanese Patent Publication No. 4-032775. It can manufacture using the method as described in gazette gazette (reference document 3) etc.

  In particular, in an orifice plate having a large number of orifices on the bottom surface, an orifice plate that surrounds a plurality of orifice outlets and has a convex edge extending downward from the bottom surface, or an outer peripheral portion of a nozzle tip having one or more orifice holes A glass fiber having a flatness ratio of 1.5 or more manufactured by using any one of the irregular-shaped glass fiber spinning nozzle tips provided with a plurality of convex edges extending downward from the tip is preferable. In these fibrous reinforcing materials, fiber strands may be used as rovings as they are, or may be used as chopped glass strands after obtaining a cutting step.

  In the present specification, “number average fiber diameter” and “weight average fiber length” are values obtained by the following methods. First, the polyamide composition is put into an electric furnace, and the contained organic matter is incinerated. 100 or more glass fibers (or carbon fibers) are arbitrarily selected from the residue after the treatment. Next, the number average fiber diameter is obtained by observing with a scanning electron microscope (SEM) and measuring the fiber diameter of these glass fibers (or carbon fibers). In addition, an SEM photograph is taken at a magnification of 1,000 times for the 100 or more glass fibers (or carbon fibers). Next, the weight average fiber length is obtained by measuring the fiber length using the SEM photograph.

The glass fiber or carbon fiber may be subjected to a surface treatment with a silane coupling agent or the like.
Examples of the silane coupling agent include, but are not limited to, amino silanes, mercapto silanes, epoxy silanes, vinyl silanes, and the like.
Examples of aminosilanes include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, and the like.
Examples of mercaptosilanes include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and the like.
These silane coupling agents may be used alone or in combination of two or more.
Of these, aminosilanes are preferred as the silane coupling agent.

Moreover, about said glass fiber or carbon fiber, you may contain a sizing agent further.
Examples of the sizing agent include copolymers and epoxy compounds containing, as structural units, unsaturated vinyl monomers containing carboxylic acid anhydrides and unsaturated vinyl monomers excluding unsaturated vinyl monomers containing carboxylic acid anhydrides. , 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 the mechanical strength of the resulting polyamide composition, as a sizing agent, unsaturated vinyl monomer excluding unsaturated vinyl monomer containing carboxylic acid anhydride and unsaturated vinyl monomer containing carboxylic acid anhydride 1 type or more chosen from the group which consists of a copolymer which contains a body as a structural unit, an epoxy compound, and a polyurethane resin is preferable. Also selected from the group consisting of copolymers and polyurethane resins containing as constituent units carboxylic anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers excluding carboxylic anhydride-containing unsaturated vinyl monomers. One or more selected from the above are more preferable.

The glass fiber or the carbon fiber is continuously produced by drying the fiber strand produced by applying the sizing agent to the fiber using a known method such as a roller type applicator in the known fiber production process. Obtained by reaction.
The fiber strand may be used as it is as roving, or may be used as a chopped glass strand after further obtaining a cutting step.
The sizing agent preferably imparts (adds) about 0.2% by mass or more and 3% by mass or less as a solid content with respect to the total mass of the glass fiber or carbon fiber, and 0.3% by mass or more and 2% by mass. It is more preferable to give (add) the following degree.
When the addition amount of the sizing agent is not less than the above lower limit as the solid content with respect to the total mass of the glass fiber or carbon fiber, the sizing of the fiber can be more effectively maintained. On the other hand, when the addition amount of the sizing agent is not more than the upper limit mass% as a solid content with respect to the total mass of the glass fiber or carbon fiber, the thermal stability of the obtained polyamide composition is further improved.

  The strand may be dried after the cutting step, or may be cut after the strand is dried.

  Inorganic fillers other than glass fiber and carbon fiber include wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fiber, boron from the viewpoint of improving the strength, rigidity and surface appearance of the molded product. Aluminum acid fiber or clay is preferred. More preferred is wollastonite, kaolin, mica, talc, calcium carbonate or clay. More preferred is wollastonite, kaolin, mica or talc. Wollastonite, mica or talc is particularly preferred. These inorganic fillers may be used individually by 1 type, and may be used in combination of 2 or more type.

The average particle diameter of the inorganic filler other than glass fiber and carbon fiber is preferably 0.01 μm or more and 38 μm or less, more preferably 0.03 μm or more and 30 μm or less, from the viewpoint of improving toughness and the surface appearance of the molded product. 0.05 to 25 μm is more preferable, 0.10 to 20 μm is still more preferable, and 0.15 to 15 μm is particularly preferable.
By setting the average particle diameter of the inorganic filler other than the glass fiber and the carbon fiber to the upper limit value or less, it is possible to obtain a polyamide composition that is superior in toughness and the surface appearance of a molded product. On the other hand, by setting the average particle size to be equal to or more than the above lower limit value, a polyamide composition excellent in balance between cost and powder handling surface and physical properties (fluidity, etc.) can be obtained.

  For needle-like inorganic fillers other than glass fibers and carbon fibers, the number average particle diameter (hereinafter sometimes simply referred to as “average particle diameter”) is defined as the average particle diameter. When the cross section is not a circle, the maximum value of the length is taken as the number average particle diameter.

  Regarding the number average particle length of the needle-shaped inorganic filler described above (hereinafter sometimes simply referred to as “average particle length”), the above-described preferred range of the number average particle diameter and the following number average particle diameter ( A numerical range calculated from a preferable range of the aspect ratio (L / D) of the number average particle length (L) to D) is preferable.

  Although it has a needle-like shape, the aspect ratio (L / D) of the number average particle length (L) to the number average particle diameter (D) improves the surface appearance of the molded product, From the viewpoint of preventing wear of the metallic part, 1.5 to 10 is preferable, 2.0 to 5 is more preferable, and 2.5 to 4 is more preferable.

  Mica used as an inorganic filler other than glass fiber and carbon fiber is preferably mascobite, flocobite, biotite, sericite or margarite from the viewpoint of improving the strength, rigidity and surface appearance of the molded product. Muscovite or flocovite are more preferred. Moreover, the wear of the apparatus at the time of extrusion and a shaping | molding process can be suppressed more by using a flocovite. These mica may be used individually by 1 type, and may be used in combination of 2 or more type.

The inorganic filler other than glass fiber and carbon fiber may be subjected to surface treatment using a silane coupling agent, a titanate coupling agent, or the like.
As a silane coupling agent, the thing similar to what was illustrated in the said glass fiber and carbon fiber is mentioned.
Of these, aminosilanes are preferred as the silane coupling agent.

  Such a surface treating agent may be previously treated on the surface of the inorganic filler, or may be added when the polyamide and the inorganic filler are mixed. Moreover, the addition amount of the surface treatment agent is preferably 0.05% by mass or more and 1.5% by mass or less with respect to the total mass of the inorganic filler.

(C) The content of the inorganic filler is 5 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the total polyamide ((A) aliphatic polyamide and (B) semiaromatic polyamide) in the polyamide composition. Preferably, 30 parts by weight or more and 250 parts by weight or less are more preferred, 50 parts by weight or more and 240 parts by weight or less are more preferred, 50 parts by weight or more and 200 parts by weight or less are particularly preferred, and 50 parts by weight or more and 150 parts by weight or less are most preferred.
(C) By making content of an inorganic filler into the above-mentioned lower limit value or more with respect to 100 parts by mass of the total polyamide in the polyamide composition, an effect of further improving the strength and rigidity of the obtained polyamide composition is manifested. Is done. On the other hand, by setting the content of the inorganic filler (C) to the upper limit value or less with respect to 100 parts by mass of the total polyamide in the polyamide composition, a polyamide composition excellent in extrudability and moldability is obtained. Can do.

  In the polyamide composition of the present embodiment, in addition to the components (A) and (B), (D) a nucleating agent, (E) a lubricant, (F) a thermal stabilizer, (G) the above (A) Aliphatic polyamides and (B) other resins other than semi-aromatic polyamides, (H) at least one selected from the group consisting of metal phosphites and metal hypophosphites, and (I) It may further include at least one selected from the group consisting of phosphate esters.

[(D) Nucleator]
(D) The nucleating agent means a substance that can obtain at least one of the following effects (1) to (3) by addition.
(1) The effect of increasing the crystallization peak temperature of the polyamide composition.
(2) The effect of reducing the difference between the extrapolation start temperature and the extrapolation end temperature of the crystallization peak.
(3) The effect of refining the spherulites of the obtained molded product or making the size uniform.

Examples of the nucleating agent (D) include, but are not limited to, talc, boron nitride, mica, kaolin, silicon nitride, carbon black, potassium titanate, molybdenum disulfide, and the like.
(D) Only one type of nucleating agent may be used alone, or two or more types may be used in combination.
Among these, as the nucleating agent (D), talc or boron nitride is preferable from the viewpoint of the nucleating agent effect.

  Further, since the effect of the nucleating agent is high, the number average particle diameter of the (D) nucleating agent is preferably 0.01 μm or more and 10 μm or less.

  The number average particle diameter of the nucleating agent can be measured using the following method. First, the molded product is dissolved in a solvent in which polyamide such as formic acid is soluble. Next, for example, 100 or more nucleating agents are arbitrarily selected from the obtained insoluble components. Subsequently, it can obtain | require by observing with an optical microscope, a scanning electron microscope, etc., and measuring a particle size.

The content of the (D) nucleating agent in the polyamide composition of the present embodiment is based on 100 parts by mass of the total polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) in the polyamide composition. 0.001 to 1 part by mass is preferable, 0.001 to 0.5 part by mass is more preferable, and 0.001 to 0.09 part by mass is further preferable.
(D) By making content of a nucleating agent more than the said lower limit with respect to 100 mass parts of polyamides, it exists in the tendency which the heat resistance of a polyamide composition improves more, and (D) nucleating agent. When the content of is set to the upper limit value or less with respect to 100 parts by mass of the polyamide, a polyamide composition having superior toughness can be obtained.

[(E) Lubricant]
The (E) lubricant contained in the polyamide composition of the present embodiment is not particularly limited, and examples thereof include higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides.

(Higher fatty acid)
Examples of higher fatty acids include linear or branched, saturated or unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms.
Examples of the linear or branched, saturated or unsaturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include lauric acid, palmitic acid, stearic acid, behenic acid, and montanic acid.
Examples of the branched saturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include isopalmitic acid and isostearic acid.
Examples of the linear unsaturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include oleic acid and erucic acid.
Examples of the branched unsaturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include isooleic acid.
Of these, stearic acid or montanic acid is preferred as the higher fatty acid.

(Higher fatty acid metal salt)
A higher fatty acid metal salt is a metal salt of a higher fatty acid.
Examples of the metal element of the metal salt include group 1 element, group 2 element and group 3 element, zinc, aluminum and the like in the periodic table.
Examples of Group 1 elements of the Periodic Table of Elements include sodium and potassium.
Examples of Group 2 elements of the Periodic Table of Elements include calcium and magnesium.
Examples of the Group 3 element in the periodic table include scandium and yttrium.
Especially, the 1st and 2nd group elements of an element periodic table, or aluminum is preferable, and sodium, potassium, calcium, magnesium, or aluminum is more preferable.

Specific examples of the higher fatty acid metal salt include calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, calcium palmitate and the like.
Among these, as the higher fatty acid metal salt, a metal salt of montanic acid or a metal salt of stearic acid is preferable.

(Higher fatty acid ester)
The higher fatty acid ester is an esterified product of a higher fatty acid and an alcohol.
The higher fatty acid ester is preferably an ester of an aliphatic carboxylic acid having 8 to 40 carbon atoms and an aliphatic alcohol having 8 to 40 carbon atoms.
Examples of the aliphatic alcohol having 8 to 40 carbon atoms include stearyl alcohol, behenyl alcohol, lauryl alcohol, and the like.

  Specific examples of the higher fatty acid ester include stearyl stearate and behenyl behenate.

(Higher fatty acid amide)
A higher fatty acid amide is an amide compound of a higher fatty acid.
Examples of the higher fatty acid amide include stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearyl amide, ethylene bisoleyl amide, N-stearyl stearic acid amide, N-stearyl erucic acid amide and the like.
These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters and higher fatty acid amides may be used alone or in combination of two or more.

The content of the (E) lubricant in the polyamide composition of the present embodiment is 0 with respect to 100 parts by mass of the total polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) in the polyamide composition. 0.001 to 1 part by mass is preferable, and 0.03 to 0.5 part by mass is more preferable.
(E) When the content of the lubricant is within the above range, it is possible to obtain a polyamide composition which is excellent in releasability and plasticization time stability and excellent in toughness. Moreover, the extreme molecular weight fall of the polyamide by a molecular chain being cut | disconnected can be prevented more effectively.

[(F) Heat stabilizer]
(F) The heat stabilizer is not limited to the following, but includes, for example, phenol-based heat stabilizers, phosphorus-based heat stabilizers, amine-based heat stabilizers, Group 3, Group 4 and Group 11 of the Periodic Table of Elements. -14 group element metal salts, alkali metal and alkaline earth metal halides, and the like.

(Phenol heat stabilizer)
Examples of the phenol-based heat stabilizer include, but are not limited to, hindered phenol compounds. The hindered phenol compound has a property of imparting excellent heat resistance and light resistance to resins and fibers such as polyamide.

Examples of the hindered phenol compound include, but are not limited to, for example, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropylene). Onamide), pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl- 4-hydroxy-hydrocinnamamide), triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3 -T-butyl-4-hydroxy-5-methylphenyl) propynyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) Examples include benzene and 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.
These hindered phenol compounds may be used alone or in combination of two or more.
In particular, from the viewpoint of improving heat aging resistance, the hindered phenol compound may be N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide). )] Is preferred.

When a phenol-based heat stabilizer is used, the content of the phenol-based heat stabilizer in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less based on the total mass of the polyamide composition. More preferably, the content is from 1% by mass to 1% by mass.
When content of a phenol type heat stabilizer exists in said range, the heat-resistant aging property of a polyamide composition can be improved further, and also the amount of gas generation can be reduced more.

(Phosphorus heat stabilizer)
Examples of the phosphorus-based heat stabilizer include, but are not limited to, pentaerythritol phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl. Phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2 , 4-di-t-butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, 4,4′-butylidene- Bis (3-methyl-6-t-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4'-isopropylidene diphenyldiphosphite, 4,4'-isopropylidenebis (2 -T-butylphenyl) -di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-t-butyl-4-hydroxyphenyl) Butane diphosphite, tetra (tridecyl) -4,4′-butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4′-isopropylidene diphenyl diphosphite , Tris (mono, dimixed nonylphenyl) phosphite, 4,4'-isopropylidene (2-t-butylphenyl) -di (nonylphenyl) phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris (3 5-di-t-butyl-4-hydroxyphenyl) phosphite, hydrogenated-4,4′-isopropylidene diphenyl polyphosphite, bis (octylphenyl) -bis (4,4′-butylidenebis (3-methyl-) 6-t-butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) diphosphite, tris (4 4′-isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylenebis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylene diphosphite and tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene diphos Fight etc. are mentioned.
These phosphorus heat stabilizers may be used alone or in combination of two or more.
Among them, as the phosphorous heat stabilizer, pentaerythritol phosphite compounds and tris (2,4-di-t-butylphenyl) are used from the viewpoint of further improving the heat aging resistance of the polyamide composition and reducing the amount of gas generated. ) One or more selected from the group consisting of phosphites are preferred.

Examples of the pentaerythritol type phosphite compound include, but are not limited to, 2,6-di-t-butyl-4-methylphenyl-phenyl-pentaerythritol diphosphite, 2,6-di- t-butyl-4-methylphenyl-methyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-2-ethylhexyl-pentaerythritol diphosphite, 2,6-di-t- Butyl-4-methylphenyl-isodecyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-lauryl-pentaerythritol diphosphite, 2,6-di-t-butyl-4- Methylphenyl-isotridecyl-pentaerythritol diphosphite, 2,6-di-t-butyl -4-methylphenyl-stearyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl cyclohexyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methyl Phenyl-benzyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl ethyl cellosolve-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-butyl Carbitol-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-nonylphenyl Pentaerythritol diphosphite, bis (2,6-di t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, 2,6-di-t-butyl-4- Methylphenyl-2,6-di-t-butylphenyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-2,4-di-t-butylphenyl-pentaerythritol diphosphite Phyto, 2,6-di-t-butyl-4-methylphenyl-2,4-di-t-octylphenyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-2 -Cyclohexylphenyl-pentaerythritol diphosphite, 2,6-di-t-amyl-4-methylphenyl-phenyl pentaeryth Tritol diphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6-di-t-octyl-4-methylphenyl) pentaerythritol di A phosphite etc. are mentioned.
These pentaerythritol phosphite compounds may be used alone or in combination of two or more.
Among them, as the pentaerythritol type phosphite compound, from the viewpoint of reducing the gas generation amount of the polyamide composition, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, , 6-Di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6 1 or more selected from the group consisting of -di-t-octyl-4-methylphenyl) pentaerythritol diphosphite is preferred, and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphos Fight is more preferred.

When using a phosphorus heat stabilizer, the content of the phosphorus heat stabilizer in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less, based on the total mass of the polyamide composition. More preferably, the content is from 1% by mass to 1% by mass.
When the content of the phosphorous heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generated can be further reduced.

(Amine heat stabilizer)
Examples of the amine heat stabilizer include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetra. Methylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6 6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6 6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethyl Peridine, 4- (ethylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy)- 2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl)- Oxalate, bis (2,2,6,6-tetramethyl-4-piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -sebacate, bis (2,2,6, 6-tetramethyl-4-piperidyl) -adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) -terephthalate, 1,2-bis (2, , 6,6-tetramethyl-4-piperidyloxy) -ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2, 6,6-tetramethyl-4-piperidyltolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris ( 2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1, 3,4-tricarboxylate, 1- [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} butyl] -4- [3- (3,5-di- t-Butyl-4-hydroxyfe L) propionyloxy] 2,2,6,6-tetramethylpiperidine, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, and a condensate with β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol.
These amine heat stabilizers may be used alone or in combination of two or more.

When the amine heat stabilizer is used, the content of the amine heat stabilizer in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less based on the total mass of the polyamide composition. More preferably, the content is from 1% by mass to 1% by mass.
When the content of the amine heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the gas generation amount can be further reduced.

(Metal salts of elements of Groups 3, 4, and 11-14 of the Periodic Table of Elements)
The metal salts of the elements of Group 3, Group 4 and Groups 11-14 of the Periodic Table of Elements are not limited as long as they are salts of metals belonging to these groups.
Among these, a copper salt is preferable from the viewpoint of further improving the heat aging resistance of the polyamide composition. Examples of the copper salt include, but are not limited to, for example, copper halide, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, stearic acid Examples thereof include copper and a copper complex salt in which copper is coordinated to a chelating agent.
Examples of the copper halide include copper iodide, cuprous bromide, cupric bromide, cuprous chloride and the like.
Examples of chelating agents include ethylenediamine and ethylenediaminetetraacetic acid.
These copper salts may be used individually by 1 type, and may be used in combination of 2 or more type.
Among them, the copper salt is preferably at least one selected from the group consisting of copper iodide, cuprous bromide, cupric bromide, cuprous chloride and copper acetate, and consists of copper iodide and copper acetate. One or more selected from the group is more preferred. When the preferred copper salts listed above are used, they are superior in heat aging resistance, and more effectively suppress the metal corrosion of the screw and cylinder during extrusion (hereinafter sometimes referred to simply as “metal corrosion”). A possible polyamide composition is obtained.

(F) When using a copper salt as a heat stabilizer, the content of the copper salt in the polyamide composition is 0 with respect to the total mass of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide). 0.01 mass% or more and 0.60 mass% or less are preferable, and 0.02 mass% or more and 0.40 mass% or less are more preferable.
When the content of the copper salt is within the above range, the heat aging resistance of the polyamide composition can be further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

Further, the content of the copper element derived from the copper salt is 10 ⁶ parts by mass of polyamide ((A) aliphatic polyamide and (B) semiaromatic polyamide) from the viewpoint of improving the heat aging resistance of the polyamide composition. The amount is preferably 10 parts by mass or more and 2000 parts by mass or less, more preferably 30 parts by mass or more and 1500 parts by mass or less, and further preferably 50 parts by mass or more and 500 parts by mass or less with respect to (1 million parts by mass).

(Alkali metal and alkaline earth metal halides)
Examples of alkali metal and alkaline earth metal halides include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and the like.
One of these alkali metal and alkaline earth metal halides may be used alone, or two or more thereof may be used in combination.
Among them, the alkali metal and alkaline earth metal halide is preferably at least one selected from the group consisting of potassium iodide and potassium bromide from the viewpoint of improving heat aging resistance and suppressing metal corrosion. Potassium is more preferred.

When alkali metal and alkaline earth metal halides are used, the content of alkali metal and alkaline earth metal halides in the polyamide composition is polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide. ) 0.05 parts by mass or more and 20 parts by mass or less is preferable, and 0.2 parts by mass or more and 10 parts by mass or less is more preferable with respect to 100 parts by mass.
When the content of alkali metal and alkaline earth metal halide is within the above range, the heat resistance aging property of the polyamide composition can be further improved, and copper precipitation and metal corrosion can be more effectively suppressed. it can.

As the component of the (F) heat stabilizer described above, only one kind may be used alone, or two or more kinds may be used in combination.
Among these, as the heat stabilizer (F), a mixture of a copper salt and a halide of an alkali metal and an alkaline earth metal is preferable from the viewpoint of further improving the heat aging resistance of the polyamide composition.

The content ratio between the copper salt and the halide of the alkali metal and alkaline earth metal is preferably 2/1 or more and 40/1 or less, preferably 5/1 or more and 30 / as the molar ratio of halogen to copper (halogen / copper). 1 or less is more preferable.
When the molar ratio of halogen to copper (halogen / copper) is within the above range, the heat aging resistance of the polyamide composition can be further improved.
Moreover, when the molar ratio of halogen to copper (halogen / copper) is not less than the above lower limit value, copper precipitation and metal corrosion can be more effectively suppressed. On the other hand, when the molar ratio of halogen to copper (halogen / copper) is less than or equal to the above upper limit, corrosion of the screws of the molding machine can be more effectively prevented without substantially impairing mechanical properties (toughness and the like).

[(G) Other resins]
The (G) other resin contained in the polyamide composition of the present embodiment is not limited to the following, but examples thereof include (A) aliphatic polyamides other than aliphatic polyamides, polyesters, liquid crystal polyesters, and polyphenylene sulfide. , Polyphenylene ether, polycarbonate, polyarylate, phenol resin, epoxy resin, acrylic resin and the like.

((A) Aliphatic polyamide other than aliphatic polyamide)
Examples of the aliphatic polyimide other than the above (A) aliphatic polyamide include, but are not limited to, polyamide 66 (PA66), polyamide 46 (PA46), polyamide 610 (PA610), and polyamide 612 (PA612). Etc. Since PA66 is excellent in heat resistance, moldability, and toughness, it is considered as a material suitable for automotive parts. Long chain aliphatic polyamides such as PA610 are excellent in chemical resistance.

(polyester)
Examples of polyester include, but are not limited to, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate, and polyethylene naphthalate.

The content of (G) other resin in the polyamide composition of the present embodiment is 0 with respect to 100 parts by mass of the total polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) in the polyamide composition. The mass is preferably from 100 parts by mass to 100 parts by mass, more preferably from 0 to 50 parts by mass, still more preferably from 0 to 10 parts by mass, particularly preferably from 0 to 5 parts by mass.
When the content of the (G) other resin in the polyamide composition of the present embodiment is within the above range, a polyamide composition excellent in heat resistance, releasability, and weather resistance can be obtained.

[(H) At least one selected from the group consisting of metal phosphite and metal hypophosphite]
Examples of the phosphorous acid metal salt and hypophosphorous acid metal salt contained in the polyamide composition of the present embodiment include phosphorous acid, hypophosphorous acid, pyrophosphorous acid, or diphosphorous acid, and a periodic table. Examples thereof include salts with elements of Group 1 and Group 2, manganese, zinc, aluminum, ammonia, alkylamine, cycloalkylamine, or diamine.
Especially, as a metal phosphite salt and a metal hypophosphite, sodium hypophosphite, calcium hypophosphite, or magnesium hypophosphite is preferable.
By including at least one selected from the group consisting of these metal phosphite salts and metal hypophosphite salts, a polyamide composition that is superior in extrusion processability and molding process stability can be obtained.

[(I) Phosphite compound]
Examples of the phosphite compound contained in the polyamide composition of the present embodiment include triphenyl phosphite and tributyl phosphite.
By adding a phosphite compound, a polyamide composition that is more excellent in extrusion processability and molding process stability can be obtained.

Specific examples of the phosphite compound include, for example, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl-diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phos Phyto, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyl tridecyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite, bis (2,6 -G-t Butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 4,4′-butylidene-bis (3-methyl-6) -T-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-ditridecylphosphite-5-t-butyl-phenyl) butane, 4,4'-isopropylidenebis (Phenyl-dialkyl phosphite), tris (2,4-di-t-butylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, bis (2,6 -Di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite.
These phosphite compounds may be used alone or in combination of two or more.

[(J) Other additives]
The polyamide composition of the present embodiment is conventionally used for polyamides in the range where the effects of the polyamide composition of the present embodiment are not impaired in addition to the components (A) and (B) (J). Other additives can also be contained. (J) Other additives include, for example, colorants (including colored masterbatches) such as pigments and dyes, flame retardants, fibrillating agents, fluorescent bleaching agents, plasticizers, antioxidants, ultraviolet absorbers, and charging. Examples thereof include an inhibitor, a fluidity improver, a spreading agent, and an elastomer.

  When the polyamide composition of this embodiment contains (J) other additives, the content of (J) other additives varies depending on the type, use of the polyamide composition, and the like. If it is a range which does not impair the effect of a polyamide composition, it will not restrict | limit in particular.

<Production method of polyamide composition>
The production method of the polyamide composition of the present embodiment is not particularly limited as long as it is a production method including a step of melting and kneading the raw material components including the (A) aliphatic polyamide and the (B) semi-aromatic polyamide. It is not something.

  For example, the method includes a step of melt-kneading a raw material component containing the (A) aliphatic polyamide and the (B) semi-aromatic polyamide with an extruder, and setting the temperature of the extruder to the melting peak temperature Tm2 + 30 of the polyamide composition. The method of making it into ℃ or less is preferred.

Examples of the method for melt-kneading the raw material component containing polyamide include the following method (1) or (2).
(1) A method in which polyamide and other raw materials are mixed using a tumbler, Henschel mixer, etc., and supplied to a melt kneader to knead.
(2) A method of blending other raw materials from a side feeder into polyamide melted by a single screw or twin screw extruder.

  In the method of supplying the components constituting the polyamide 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 melt kneading temperature is preferably about 250 ° C. or higher and 350 ° C. or lower as the resin temperature.
The melt kneading time is preferably about 0.25 minutes or more and 5 minutes or less.
The apparatus for performing melt kneading is not particularly limited, and a known apparatus such as a single or twin screw extruder, a Banbury mixer, a melt kneader (such as a mixing roll), or the like can be used.
The compounding quantity of each component at the time of manufacturing the polyamide composition of this embodiment is the same as the content of each component in the polyamide composition described above.

≪Molded product≫
The molded product of this embodiment is formed by molding the polyamide composition of the above embodiment.

<Surface gloss value>
Moreover, the molded product of this embodiment has a high surface gloss value. The surface gloss value of the molded product of this embodiment is preferably 80 or more, more preferably 81 or more, and still more preferably 85 or more. As the surface gloss value of the molded product is equal to or higher than the lower limit, the obtained molded product can be used as various parts for automobiles, electrical and electronic products, industrial materials, industrial materials, and daily and household products. It can be preferably used.
The surface gloss value can be measured by the method shown in Examples described later.

<Molding method>
The molded product of this embodiment can be obtained, for example, by molding the above-described polyamide composition by a known molding method.
Known molding methods include, but are not limited to, for example, press molding, injection molding, gas assist injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, and melt spinning. And generally known plastic molding methods.

<Application>
Since the molded article of this embodiment is obtained from the above-mentioned polyamide composition, it is excellent in moldability, mechanical strength, low water absorption, and surface appearance. Therefore, the molded product of the present embodiment includes various parts such as various sliding parts, automobile parts, electric and electronic parts, home appliance parts, OA (Office Automation) equipment parts, portable equipment parts, industrial equipment parts, daily necessities, and household goods. Moreover, it can use suitably for an extrusion use etc. Among these, the molded product of the present embodiment is suitably used as an automobile part, an electronic part, a home appliance part, an OA equipment part, or a portable equipment part.
Although it does not specifically limit as an automotive component, For example, an intake system component, a cooling system component, a fuel system component, an interior component, an exterior component, an electrical component, etc. are mentioned.
The automobile intake system parts are not particularly limited, and examples thereof include an air intake manifold, an intercooler inlet, an exhaust pipe cover, an inner bush, a bearing retainer, an engine mount, an engine head cover, a resonator, and a throttle body.
Although it does not specifically limit as a motor vehicle cooling system component, For example, a chain cover, a thermostat housing, an outlet pipe, a radiator tank, an alternator, a delivery pipe etc. are mentioned.
Although it does not specifically limit in an automotive fuel system component, For example, a fuel delivery pipe, a gasoline tank case, etc. are mentioned.
Although it does not specifically limit as a vehicle interior component, For example, an instrument panel, a console box, a glove box, a steering wheel, a trim, etc. are mentioned.
Although it does not specifically limit as an automotive exterior component, For example, a mall, a lamp housing, a front grill, a mud guard, a side bumper, a door mirror stay, a roof rail, etc. are mentioned.
Although it does not specifically limit as a motor vehicle electrical component, For example, a connector, a wire harness connector, a motor component, a lamp socket, a sensor vehicle-mounted switch, a combination switch etc. are mentioned.
Although it does not specifically limit as an electrical and electronic component, For example, a connector, the reflector for light-emitting devices, a switch, a relay, a printed wiring board, the housing of an electronic component, an outlet, a noise filter, a coil bobbin, a motor end cap etc. are mentioned.
Reflectors for light emitting devices include semiconductor packages such as light diodes (LEDs) as well as optical semiconductors such as laser diodes (LD), photo diodes, charge coupled devices (CCD), and complementary metal oxide semiconductors (CMOS). Can be widely used for.
Although it does not specifically limit as portable apparatus components, For example, housing | casings and structures, such as a mobile telephone, a smart phone, a personal computer, a portable game device, a digital camera, etc. are mentioned.
Although it does not specifically limit as industrial equipment components, For example, a gear, a cam, an insulation block, a valve, an electric tool component, an agricultural equipment component, an engine cover etc. are mentioned.
Although it does not specifically limit as household goods and household goods, For example, a button, a food container, office furniture etc. are mentioned.
Although it does not specifically limit as an extrusion use, For example, it uses for a film, a sheet | seat, a filament, a tube, a stick | rod, a hollow molded article, etc.

The molded article of this embodiment is particularly suitable for exterior structural materials among these various uses. The exterior structural material is a mechanical part or a structural part that is required to have a molded product surface processability (for example, texture processing, high surface glossiness, etc.) and a relatively large strength and rigidity.
Specific examples of the structural material for the exterior include OA equipment field products, automobile parts, electrical field products, and other field products.
As OA equipment field products, for example, desk legs, chair legs, seats, cabins, furniture items such as parts of wagons, notebook personal computer housings and the like can be mentioned.
Examples of automobile parts include door mirror stays, wheel rims, wheel caps, wipers, motor fans, seat lock parts, gears, lamp housings, wheel rims, wheel spokes, saddles, saddle posts, handles, stands, and cargo beds. .
Examples of the electrical field article include a pulley, a gear, a hot air fan housing, and the like.
Examples of other field products include valve housings, nails, screws, bolts, bolts and nuts.

Moreover, since the molded product of this embodiment is excellent in surface appearance, it is preferably used as a molded product in which a coating film is formed on the surface of the molded product.
The method for forming the coating film is not particularly limited as long as it is a known method, and for example, it can be applied by spraying, electrostatic coating or the like.
The paint used for the coating is not particularly limited as long as it is a known one. For example, a melamine cross-linked polyester polyol resin paint, an acrylic urethane paint, or the like can be used.

  Among these, the molded product of the present embodiment is excellent in mechanical strength, toughness, heat resistance and vibration fatigue resistance, and is therefore more suitable as a component material for automobiles, and is also excellent in slidability. It is particularly suitable as a component material for gears and bearings. Moreover, since it is excellent in mechanical strength, toughness, and heat resistance, it is more suitable as a component material for electric and electronic use.

EXAMPLES Hereinafter, although a specific Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to a following example.
In this example, “1 kg / cm ² ” means 0.098 MPa.
Hereafter, each component of the polyamide composition used for the present Example and the comparative example is demonstrated.

<Constituents>
[(A) Aliphatic polyamide]
A-1: Polyamide 6 (manufactured by Meida, “M2000” (trade name), Mw = 22800, Mw / Mn: 2.1)
A-2: Polyamide 6 (manufactured by Ube Industries, “SF1013A” (trade name), Mw = 31500, Mw / Mn = 2.2)

[(B) Semi-aromatic polyamide]
B-1: Polyamide 6I (Mw: 20000, Mw / Mn: 2)
B-2: Polyamide 6I (manufactured by LANXESS, “T-40” (trade name), Mw = 44000, Mw / Mn = 2.8)
B-3: Polyamide 6I / 6T (manufactured by EMS, "Grivory 21" (trade name), Mw = 27000, Mw / Mn = 2.2)

[(C) Inorganic filler]
C-1: Glass fiber (manufactured by Nippon Electric Glass, “ECS03T275H” (trade name), number average fiber diameter 10 μm (circular shape), cut length 3 mm)
C-2: Wollastonite (manufactured by NYCO, “400WC” (trade name), number average particle diameter 8.0 μm, number average particle length 35 μm)

In this example, the number average fiber diameter of the glass fibers (C-1) was measured as follows.
First, each polyamide composition was put into an electric furnace, and the organic matter contained in each polyamide composition was incinerated. By observing 100 or more glass fibers arbitrarily selected from the residue after the treatment with a scanning electron microscope (SEM) and measuring the fiber diameters of these glass fibers, the number average fiber diameter is obtained. It was.

In this example, the number average particle diameter and number average particle length of wollastonite (C-2) were measured as follows.
First, the polyamide composition was placed in an electric furnace, and the organic matter contained in each polyamide composition was incinerated. By observing 100 or more wollastonites arbitrarily selected from the residue after the treatment with a scanning electron microscope (SEM) and measuring the particle diameter and particle length of these wollastonites, The average particle size and number average particle length were determined.

<Production of polyamide>
The (B) semi-aromatic amide B-1 (polyamide 6I) used in the present Examples and Comparative Examples was produced using the following (Ba) dicarboxylic acid and (BB) diamine as appropriate. The obtained (B) semi-aromatic amide B-1 (polyamide 6I) is used as a raw material for each polyamide composition after drying in a nitrogen stream and adjusting the water content to about 0.2% by mass. It was.

[(Ba) Dicarboxylic acid]
B-a1: Isophthalic acid (IPA) (manufactured by Wako Pure Chemical Industries)

[(B-b) diamine]
B-b1: 1,6-diaminohexane (hexamethylenediamine) (C6DA) (manufactured by Tokyo Chemical Industry)

[Synthesis Example 1] Synthesis of Semi-Aromatic Polyamide B-1 (Polyamide 6I) A polyamide polymerization reaction was carried out by the “hot melt polymerization method” as follows.
1500 g of equimolar salt of isophthalic acid and hexamethylenediamine and 1.5 mol% excess adipic acid is dissolved in 1500 g of distilled water with respect to all equimolar salt components, and equimolar 50% by mass of the raw material monomer is uniform. An aqueous solution was prepared. Subsequently, while stirring at a temperature of 110 to 150 ° C., water vapor was gradually removed to concentrate to a solution concentration of 70% by mass. Next, the internal temperature was raised to 220 ° C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing water vapor and maintaining the pressure at 1.8 MPa until the internal temperature reached 245 ° C. Next, the pressure was reduced over 30 minutes. Subsequently, the inside of the autoclave was maintained for 10 minutes under a reduced pressure of 650 torr (86.66 kPa) with a vacuum apparatus. At this time, the final internal temperature of the polymerization was 265 ° C. Next, it is pressurized with nitrogen to form a strand from the lower nozzle (nozzle), water-cooled, cut, discharged in pellet form, dried at 100 ° C. in a nitrogen atmosphere for 12 hours, and semi-aromatic polyamide B-1 (polyamide) 6I) was obtained.

  The obtained semiaromatic polyamide B-1 has Mw (B) = 20000, Mw (B) / Mn (B) = 2, and (B) aromatic dicarboxylic acid in all dicarboxylic acid units constituting the semiaromatic polyamide. The content of acid units was 100 mol%.

<Physical properties and evaluation>
First, the polyamide composition pellets obtained in the examples and comparative examples were dried in a nitrogen stream, and the water content in the polyamide composition was reduced to 500 ppm or less. Next, various physical properties and various evaluations were performed using the following methods using pellets of each polyamide composition with adjusted water content.

[Physical Property 1] Content of Aromatic Dicarboxylic Acid Unit (B) The content (mol%) of the aromatic dicarboxylic acid unit in all dicarboxylic acid units constituting the semi-aromatic polyamide is expressed by the following formula (i). Obtained by calculation.
Aromatic dicarboxylic acid unit content (mol%)
= {(Number of moles of aromatic dicarboxylic acid added as raw material monomer) / (number of moles of all dicarboxylic acids added as raw material monomer)} × 100 (i)

[Property 2] Melting peak temperature Tm2 (melting point), crystallization peak temperature Tc, and crystallization enthalpy of polyamide composition Measured using Diamond-DSC manufactured by PERKIN-ELMER according to JIS-K7121. Specifically, it measured as follows.

  First, in a nitrogen atmosphere, about 10 mg of a sample was heated from room temperature to 300 to 350 ° C. according to the melting point of the sample at a temperature rising rate of 20 ° C./min. The maximum peak temperature of the endothermic peak (melting peak) appearing at this time was defined as Tm1 (° C.). Next, the temperature was maintained for 2 minutes at the highest temperature rise. At this maximum temperature, the polyamide was in a molten state. Next, the temperature was decreased to 30 ° C. at a temperature decrease rate of 20 ° C./min. The exothermic peak appearing at this time was taken as the crystallization peak, and the crystallization enthalpy ΔH (J / g) was obtained from the crystallization peak temperature Tc and the crystallization peak area. Next, after maintaining at 30 ° C. for 2 minutes, the temperature was increased from 30 ° C. to 280 to 300 ° C. according to the melting point of the sample at a temperature increase rate of 20 ° C./min. The maximum peak temperature of the endothermic peak (melting peak) appearing at this time was defined as the melting point Tm2 (° C.).

[Physical property 3] Polyamide composition, (A) aliphatic polyamide and (B) semi-aromatic polyamide molecular weight Weight average molecular weight (Mw, Mw (A) and Mw (B)), and number average molecular weight (Mn) are Measured using GPC (gel permeation chromatography) under the following measurement conditions. Next, Mw (A) -Mn (B) and molecular weight distribution Mw / Mn were calculated based on the values obtained by GPC. Moreover, the content (mass%) of the polyamide whose number average molecular weight Mn is 500 or more and 2000 or less among the total polyamide in the polyamide composition is an elution curve (vertical axis: detector) of each sample obtained using GPC. (Horizontal axis: elution time), the area of the area of the number average molecular weight of 500 or more and less than 2000 surrounded by the baseline and the elution curve, and the total number average molecular weight surrounded by the baseline and the elution curve. Calculated from the area of the region.

(Measurement condition)
Measuring device: HLC-8020 manufactured by Tosoh Corporation
Solvent: Hexafluoroisopropanol solvent Standard sample: PMMA (polymethyl methacrylate) standard sample (manufactured by Polymer Laboratories) conversion GPC column: TSK-GEL GMHHR-M and G1000HHRGPC

[Evaluation 1] Dissolution viscosity The melt viscosity at 260 ° C and a shear rate of 100 s-1 was measured using a twin capilograph manufactured by ROSAND. The die used at this time was as follows. Moreover, it was judged that the smaller the measured value, the better the fluidity.
(Die)
Long die length (mm): 16
Long die diameter (mm): 1
Short die length (mm): 0.25
Short die diameter (mm): 1
Die entry angle (deg): 180

Moreover, preheating conditions were implemented on condition of the following.
(Preheat condition)
Initial pressure long die (MPa): 0.3
Initial pressure short die (MPa): 0.3
Time before 2nd compression (min): 3
Final pressure long die (MPa): 0.2
Preheat time (min): 2

[Evaluation 2] Surface gloss value of molded product (1) Production of molded product (flat plate molded piece) A flat plate molded piece was produced as follows.
Using an injection molding machine (NEX50III-5EG, manufactured by Nissei Plastic Industry Co., Ltd.), set the following conditions and set the injection pressure and injection speed so that the filling time is in the range of 1.6 ± 0.1 seconds. A flat plate molded piece (6 cm × 9 cm, thickness 2 mm) was produced by adjusting appropriately.
(Molding condition)
Cooling time: 25 seconds Screw rotation speed: 200 rpm
Mold temperature: 90 ℃
Cylinder temperature: (Tm2 + 10) ° C to (Tm2 + 30) ° C

(2) Measurement of surface gloss value A 60-degree gloss was measured for the central portion of the flat plate molded piece obtained in (1) using a gloss meter (manufactured by HORIBA, IG320) according to JIS-K7150. Note that the larger the measured value, the better the surface appearance.

[Evaluation 3] MD (mold deposit) during molding
Using the same method as (1) of [Evaluation 2], the molding was performed continuously for 100 shots, and the gas vent after the molding was visually confirmed. The evaluation criteria for gas generation during molding were as follows. It was evaluated that obtaining a molded product without problems would lead to improvement in productivity.

(Evaluation criteria)
A: There is no deposit on the gas vent. B: There is a deposit on the gas vent. C: There is an deposit on the gas vent and it is clogging. D: There is an deposit on the gas vent and there is a blockage.

[Evaluation 4] Tensile Strength of Molded Product (1) Manufacture of Molded Product (Multipurpose Test Specimen A Type Molded Piece) Using an injection molding machine (PS-40E, manufactured by Nissei Plastic Co., Ltd.), in accordance with ISO 3167, Each was molded into a multi-purpose test piece A-shaped molded piece. The specific molding conditions were injection + holding time 25 seconds, cooling time 15 seconds, mold temperature 80 ° C., and molten resin temperature set to the high temperature melting peak temperature (Tm2) + 20 ° C. of polyamide.

(2) Measurement of tensile strength Using the multi-purpose test piece A-shaped molded piece obtained in (1), a tensile test was performed at a tensile speed of 50 mm / min under a temperature condition of 23 ° C. in accordance with ISO 527. The tensile yield stress was measured and taken as the tensile strength. In addition, it was judged that it was excellent in intensity | strength, so that a measured value was large.

[Evaluation 5] Rigidity of molded product during water absorption (retention rate of bending elastic modulus during water absorption)
An ISO dumbbell having a thickness of 4 mm was produced and used as a test piece. Using the obtained test piece, the flexural modulus was measured according to ISO178. Further, the ISO dumbbell was left in a constant temperature and humidity (23 ° C., 50 RH%) atmosphere to reach water absorption equilibrium, and then the flexural modulus was measured according to ISO 178. The bending elastic modulus retention at the time of water absorption was determined using the following formula (ii). In addition, it was judged that the rigidity at the time of water absorption was excellent, so that the bending elastic modulus retention rate at the time of water absorption was near 100%.
Flexural modulus retention after water absorption (%)
= {(Bending elastic modulus after water absorption) / (Bending elastic modulus before water absorption)} × 100 (ii)

[Example 1] Manufacture of polyamide composition 1 As an apparatus for manufacturing a polyamide composition, a twin screw extruder (ZSK-26MC, manufactured by Coperion (Germany)) was used. The twin screw extruder has an upstream supply port in the first barrel from the upstream side of the extruder, a downstream first supply port in the sixth barrel, and a downstream second supply port in the ninth barrel. Had. In the twin screw extruder, L / D was 48 and the number of barrels was 12. In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 + 20 ° C. of each polyamide, the screw rotation speed was set to 250 rpm, and the discharge amount was set to 25 kg / h.

(A) Aliphatic polyamide A-1 and (B) semi-aromatic polyamide B-1 were dry blended and then supplied from the upstream supply port of the twin-screw extruder. Subsequently, C-1 (glass fiber) was supplied as an inorganic filler (C) from the first supply port on the downstream side of the twin-screw extruder. Moreover, C-2 (wollastonite) was supplied as (C) inorganic filler from the downstream second supply port of the twin-screw extruder. Next, the melt-kneaded product extruded from the die head was cooled in a strand shape and pelletized to obtain polyamide composition 1 pellets (including inorganic filler).
Using the obtained polyamide composition 1 pellets, a molded product was produced by the above-described method, and various physical properties and evaluation were performed. The evaluation results are shown in Table 1 below.

[Examples 2 to 4 and Comparative Examples 1 to 3] Production of polyamide compositions 2 to 4 and 5 to 7 The same method as in Example 1 except that the blending amounts were as shown in Table 1 below. Was used to obtain each pellet of polyamide compositions 2-7. Using each pellet of the obtained polyamide compositions 2 to 7, a molded product was produced by the above method, and various physical properties and evaluation were performed. The evaluation results are shown in Table 1 below.

From Table 1, 60 mass parts or more and 70 mass parts or less of (A) aliphatic polyamide A-1 or A-2, and (B) 30 mass parts or more and 40 mass parts or less of semi-aromatic polyamide B-1 are contained. In polyamide compositions 1 to 4 (Examples 1 to 4), which are polyamide compositions having Mw of 26000 or 31300, (A) 100 parts by mass of aliphatic polyamide A-1 and Mw of 24,000 5 (Comparative Example 1), (A) 65 parts by mass of aliphatic polyamide A-1 and (B) 35 parts by mass of semi-aromatic polyamide B-2 (polyamide 6I), polyamide composition 6 having Mw of 38000 (Comparative Example 2), and (A) 65 parts by mass of aliphatic polyamide A-1 and (B) 35 parts by mass of semi-aromatic polyamide B-3 (polyamide 6I / 6T), Mw of 33300 Compared to the composition 7 (Comparative Example 3), in particular, fluidity (melt viscosity is 800 Pa · s or less), surface gloss value (80 or more), MD (A) during molding, tensile strength (175 MPa or more), and The balance of the flexural modulus retention (at least 98%) at the time of water absorption was excellent.
Further, from the comparison of the polyamide compositions 1 to 3 (Examples 1 to 3), there is a tendency that the bending elastic modulus retention rate at the time of water absorption increases as the content of the (B) semi-aromatic polyamide B-1 increases. It was seen.

  The polyamide composition of this embodiment is excellent in mechanical properties, in particular, water absorption rigidity, thermal rigidity, fluidity, and surface appearance. The molded product of this embodiment contains the polyamide composition, and can be suitably used as various parts such as for automobiles, for electric and electronic use, for industrial materials, for industrial materials, and for daily use and household goods. .

Claims (15)

(A) an aliphatic polyamide, and
(B) a semi-aromatic polyamide containing a dicarboxylic acid unit and a diamine unit,
A polyamide composition comprising:
50 parts by weight or more and 99 parts by weight or less of the (A) aliphatic polyamide and 100 parts by weight of the (B) half of the total weight of the (A) aliphatic polyamide and the (B) semi-aromatic polyamide. Containing 1 to 50 parts by weight of aromatic polyamide,
The (A) aliphatic polyamide contains at least one selected from the group consisting of a lactam unit having 4 to 14 carbon atoms and an aminocarboxylic acid unit having 4 to 14 carbon atoms,
The (B) semi-aromatic polyamide comprises 75 mol% or more of isophthalic acid units in the total dicarboxylic acid units constituting the (B) semi-aromatic polyamide, and constitutes the (B) semi-aromatic polyamide. In all the diamine units, the diamine unit having 4 to 10 carbon atoms is contained in an amount of 50 mol% or more,
The polyamide composition whose weight average molecular weight Mw of the said polyamide composition is 15000 or more and 35000 or less. Furthermore, (C) containing an inorganic filler,
The polyamide composition according to claim 1, wherein the content of the (C) inorganic filler is 5 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the total polyamide in the polyamide composition.   The polyamide composition according to claim 2, wherein the shape of the inorganic filler (C) is at least one of a needle shape and a plate shape.   Among the total polyamide in the polyamide composition, the total content of polyamides having a number average molecular weight Mn of 500 or more and 2000 or less is 2.5% by mass or more and 4% by mass or more based on the total mass of the polyamide in the polyamide composition. It is less than 0.0 mass%, The polyamide composition as described in any one of Claims 1-3.   The polyamide composition according to any one of claims 1 to 4, wherein the (A) aliphatic polyamide is polyamide 6.   The polyamide composition according to any one of claims 1 to 5, wherein the (B) semi-aromatic polyamide is polyamide 6I.   The polyamide composition according to any one of claims 1 to 6, wherein the polyamide composition has a molecular weight distribution Mw / Mn of 2.4 or less.   The polyamide composition according to any one of claims 1 to 7, wherein a molecular weight distribution Mw / Mn of the polyamide composition is 2.2 or less.   The weight average molecular weight Mw (B) of said (B) semi-aromatic polyamide is 10,000-25,000, The polyamide composition as described in any one of Claims 1-8.   The polyamide composition according to any one of claims 1 to 9, wherein the molecular weight distribution Mw (B) / Mn (B) of the (B) semi-aromatic polyamide is 2.4 or less.   The difference {Mw (A) -Mw (B)} between the weight average molecular weight Mw (A) of the (A) aliphatic polyamide and the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide is less than 10,000. The polyamide composition according to any one of claims 1 to 10.   The difference {Mw (A) -Mw (B)} between the weight average molecular weight Mw (A) of the (A) aliphatic polyamide and the weight average molecular weight Mw (B) of the (B) semi-aromatic polyamide is 10,000 or more. It is 20000 or less, The polyamide composition as described in any one of Claims 1-10.   Furthermore, (H) Polyamide composition as described in any one of Claims 1-12 containing at least 1 sort (s) chosen from the group which consists of a metal phosphite salt and a hypophosphite metal salt.   Furthermore, the polyamide composition as described in any one of Claims 1-13 containing (I) phosphite compound.   A molded article obtained by molding the polyamide composition according to any one of claims 1 to 14, and having a surface gloss value of 80 or more.