JP2020055940A - Polyamide composition, molded article and semi-aromatic polyamide - Google Patents

Abstract

To provide a polyamide composition excellent in flowability and surface appearance while maintaining good water absorption rigidity and rigidity at high temperatures.SOLUTION: There is provided a polyamide composition which comprises 50 pts.mass or more and 99 pts.mass of an aliphatic polyamide (A) composed of a diamine and a dicarboxylic acid and 1 pt.mass or more and 50 pts.mass or less of a semi-aromatic polyamide (B) containing a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and a diamine unit containing at least 50 mol% of a diamine unit having 4 or more and 10 or less carbon atoms, wherein the amount of the sealed terminal represented as equivalent to 1 g of at least one polyamide selected from the group consisting of the aliphatic polyamide (A) and the semi-aromatic polyamide (B) is 5 μ equivalent/g or more and 180 μ equivalent/g or less and the polyamide composition has a tanδ peak temperature of 90°C or more.SELECTED DRAWING: None

Description

  The present invention relates to polyamide compositions, molded articles and semi-aromatic polyamides.

Polyamides represented by polyamide 6 (hereinafter, also referred to as “PA6”) and polyamide 66 (hereinafter, also referred to as “PA66”) are excellent in moldability, mechanical properties, or chemical resistance, and are therefore used for automobiles. It is widely used as various component materials for electric and electronic devices, industrial materials, industrial materials, daily products and household products.
In recent years, the usage environment of polyamide resin has become severer both thermally and mechanically, and the mechanical properties, especially the stiffness after water absorption and the stiffness under high temperature use have been improved. There is a demand for a polyamide resin material having a small content.
Further, a molded article using a polyamide resin may be molded under high cycle molding conditions in which the molding temperature is increased and the mold temperature is decreased in order to improve productivity.

On the other hand, when molding is performed under a high temperature condition, there is a problem that a molded article may not be stably obtained due to decomposition of the polyamide resin or a change in fluidity.
In particular, there is a demand for a polyamide resin having excellent stability of the surface appearance of a molded product even under the severe molding conditions as described above.

  In order to meet such demands, as a material capable of improving the surface appearance and mechanical properties of a molded product, a polyamide made of polyamide 66 / 6I into which an isophthalic acid component is introduced is disclosed (for example, Patent Document 1). . Further, as a material capable of improving mechanical properties, fluidity, surface appearance, and the like, a polyamide composition comprising polyamide 6T / 6I into which a terephthalic acid component and an isophthalic acid component are introduced is disclosed (for example, Patent Document 1). 2, 3).

JP-A-6-32980 JP 2000-154316 A JP-A-11-349806 Japanese Patent Publication No. 3-059019 Japanese Patent Publication No. 4-013300 Japanese Patent Publication No. 4-032775

However, in the techniques disclosed in Patent Documents 1 and 3, although the rigidity under normal use conditions is improved, there is room for improvement in the rigidity after water absorption and the rigidity under high-temperature use.
Further, the polyamide produced by the production technique disclosed in Patent Document 2 has improved rigidity after water absorption and rigidity under high temperature use. However, although the surface appearance of molded articles under general molding conditions is improved, under severe molding conditions such as high cycle molding conditions, there is a problem that the appearance and stability of the molded surface are reduced. ing.

  As described above, in the prior art, it is a fact that a polyamide copolymer which is excellent in rigidity after water absorption and rigidity under high temperature use and has little change in physical properties in use under any environment has not yet been known. . In addition, it is difficult to suppress a decrease in rigidity after water absorption and under high-temperature use while maintaining a balance between mechanical strength and rigidity, which is a characteristic of polyamide copolymers. There is a need for compositions and molded articles containing coalesced or polyamide.

  The present invention has been made in view of the above circumstances, and maintains good rigidity at the time of water absorption (hereinafter, referred to as water absorption rigidity) and rigidity at high temperature use (hereinafter, referred to as thermal rigidity). In addition, the present invention provides a polyamide composition excellent in fluidity and surface appearance, and a molded article comprising the polyamide composition.

That is, the present invention includes the following aspects.
A dicarboxylic acid unit containing 50 to 99 parts by mass of an aliphatic polyamide (A) comprising a diamine and a dicarboxylic acid according to the first embodiment of the present invention, and a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit; A polyamide composition containing 1 to 50 parts by mass of a semi-aromatic polyamide (B) containing at least 50 mol% of a diamine unit containing at least 50 or less diamine units of the above (A) The polyamide having a sealed terminal amount expressed as an equivalent to 1 g of at least one kind of polyamide selected from the group consisting of a polyamide and the (B) semi-aromatic polyamide, which is 5 μe / g or more and 180 μe / g or less; The tan δ peak temperature of the composition is 90 ° C. or higher.

  The amount of the terminal capped with acetic acid, expressed as an equivalent to 1 g of the semi-aromatic polyamide (B), may be from 5 μeq / g to 180 μeq / g.

  The weight average molecular weight Mw of the polyamide composition may be from 15,000 to 35,000.

  The polyamide composition may have a molecular weight distribution Mw / Mn of 2.6 or less.

  The sum of the amount of amino terminal and the amount of carboxyl terminal expressed as equivalents to 1 g of the polyamide in the polyamide composition may be 70 μe / g or more and 145 μe / g or less.

  The ratio of the amount of amino terminal to the total amount of amino terminal and carboxyl terminal {amino terminal amount / (amino terminal amount + carboxyl terminal amount)} may be 0.25 or more and less than 0.4.

  The (A) aliphatic polyamide may be polyamide 66 or polyamide 610.

  In the semi-aromatic polyamide (B), the content of the isophthalic acid unit with respect to the total amount of the dicarboxylic acid units may be 100 mol%.

  The semi-aromatic polyamide (B) may be polyamide 6I.

  The weight average molecular weight Mw (B) of the semi-aromatic polyamide (B) may be 10,000 or more and 25,000 or less.

  The molecular weight distribution Mw (B) / Mn (B) of the semi-aromatic polyamide (B) may be 2.4 or less.

  The difference (Mw (A) -Mw (B)) between the weight average molecular weight Mw (A) of the aliphatic polyamide (A) and the weight average molecular weight Mw (B) of the semiaromatic polyamide (B) is 10,000 or more. There may be.

  It may further contain at least one metal salt selected from the group consisting of metal phosphites and metal hypophosphites.

  It may further contain a phosphite compound.

  The inorganic filler (C) may further be contained in an amount of 5 to 250 parts by mass based on 100 parts by mass of the aliphatic polyamide (A) and the semi-aromatic polyamide (B) in total.

  The molded article according to the second aspect of the present invention is obtained by molding the polyamide composition according to the first aspect, and has a surface gloss value of 50 or more.

  The semi-aromatic polyamide according to the third aspect of the present invention is a semi-aromatic polyamide containing a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and a diamine unit composed of a linear aliphatic diamine having 4 to 10 carbon atoms. An aromatic polyamide, wherein the amount of the capped terminal expressed as an equivalent to 1 g of the semi-aromatic polyamide is 5 μe / g or more and 180 μe / g or less, and the tan δ peak temperature of the semi-aromatic polyamide is 90 ° C. That is all.

  The amount of the terminal capped with acetic acid, expressed as an equivalent to 1 g of the semi-aromatic polyamide, may be 5 μe / g or more and 180 μe / g or less.

  The sum of the amount of amino terminal and the amount of carboxyl terminal expressed as equivalents to 1 g of the semi-aromatic polyamide may be 50 μe / g or more and 155 μe / g or less.

  The weight average molecular weight Mw of the semi-aromatic polyamide may be 10,000 or more and 35,000 or less.

  The molecular weight distribution Mw / Mn of the semi-aromatic polyamide may be 2.6 or less.

  According to the polyamide composition and the semi-aromatic polyamide of the above embodiment, a molded article having excellent fluidity and surface appearance can be obtained while maintaining good water absorption rigidity and hot rigidity. The molded article of the present embodiment is excellent in fluidity and surface appearance while maintaining good water absorption rigidity and rigidity when heated.

  Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for describing the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the invention.

  In addition, in this 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) 50 to 99 parts by mass of an aliphatic polyamide and (B) 1 to 50 parts by mass of a semi-aromatic polyamide. (A) The aliphatic polyamide comprises a diamine and a dicarboxylic acid. (B) The semi-aromatic polyamide contains a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and a diamine unit containing at least 50 mol% of a diamine unit having 4 to 10 carbon atoms.
In the polyamide composition of the present embodiment, the sealed terminal amount expressed as an equivalent to 1 g of at least one kind of polyamide selected from the group consisting of (A) an aliphatic polyamide and (B) a semi-aromatic polyamide is 5 μ equivalent. / G or more and 180 µeq / g or less.
The tan δ peak temperature of the polyamide composition of the present embodiment is 90 ° C. or higher.

  Since the polyamide composition of the present embodiment has the above-described configuration, a molded article having excellent water absorption rigidity, rigidity at heat, fluidity, and surface appearance can be obtained.

The semi-aromatic polyamide of the present embodiment contains a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and a diamine unit composed of a linear aliphatic diamine having 4 to 10 carbon atoms.
In the semi-aromatic polyamide of the present embodiment, the amount of the capped terminal expressed as an equivalent to 1 g of the semi-aromatic polyamide is from 5 μeq / g to 180 μeq / g.
The tan δ peak temperature of the semi-aromatic polyamide of this embodiment is 90 ° C. or higher.

  The semi-aromatic polyamide of the present embodiment having the above-described configuration can provide a molded article having excellent fluidity, surface appearance, and corrosion resistance while maintaining good water absorption rigidity and rigidity when heated.

As the semi-aromatic polyamide, a semi-aromatic polyamide (B) described later can be used.
In addition, as the semi-aromatic polyamide of the present embodiment, a semi-aromatic polyamide composition can be obtained by adding an inorganic filler and additives described below. The semi-aromatic polyamide composition preferably contains 90% or more of the semi-aromatic polyamide.

<Characteristics of polyamide composition>
The molecular weight, melting point Tm2, crystallization enthalpy ΔH, tan δ peak temperature, sealed terminal amount, amino terminal amount and carboxy terminal amount of the polyamide composition obtained by the production method of the present embodiment can be configured as follows. Can be measured by the method described in Examples described later.

[Molecular weight of polyamide composition]
As an index of the molecular weight of the polyamide composition, a weight average molecular weight (Mw) can be used. The weight average molecular weight (Mw) of the polyamide composition is preferably from 15,000 to 35,000, more preferably from 17,000 to 35,000, still more preferably from 20,000 to 35,000, still more preferably from 22,000 to 34,000, particularly preferably from 24,000 to 33,000. , 25,000 or more and 32,000 or less.
When the weight average molecular weight (Mw) is within the above range, a polyamide composition having excellent mechanical properties, particularly excellent water absorption stiffness, heat stiffness, fluidity, corrosion resistance, and the like can be obtained. Further, a polyamide composition containing a component represented by an inorganic filler has more excellent surface appearance.
Examples of a method for controlling the Mw of the polyamide composition within the above range include using (A) an aliphatic polyamide and (B) a semiaromatic polyamide having a weight average molecular weight in the above range.
In addition, Mw can be measured using gel permeation chromatography (GPC) as described in the following Examples.

[Of the total polyamides in the polyamide composition, the total content of those having a number average molecular weight Mn of 500 or more and 2000 or less]
Among the total polyamides 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 0.5% by mass or more and 2.5% by mass relative to the total mass of the polyamides in the polyamide composition. %, Preferably from 0.5% by mass to 2.0% by mass, more preferably from 0.5% by mass to 1.5% by mass, more preferably from 0.5% by mass to 1.0% by mass. Particularly preferred is 0.6% by mass or more and 0.9% by mass or less.
Out of the total polyamides 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 not less than the lower limit, so that the fluidity is excellent and (C) an inorganic filler is typical. There is a tendency that a molded article obtained from a polyamide composition containing the component described above can be made more excellent in surface appearance. Further, when the total content is less than the upper limit, gas generation during molding tends to be more effectively suppressed.
In order to control the total content of those having a number average molecular weight Mn of 500 or more and 2000 or less in the above range among the total polyamides in the polyamide composition, it is expressed as an equivalent to 1 g of the semi-aromatic polyamide (B). The amount of the capped terminal is important, and it is preferable to control the amount of the capped terminal to be 5 μeq / g or more and 180 μeq / g or less. Further, the weight average molecular weight (Mw (B)) of the semiaromatic polyamide (B) is also important, and it is preferable to control the Mw (B) to be 10,000 or more and 25,000 or less.

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

[Difference (Mw (A) -Mw (B)} between (A) weight average molecular weight Mw (A) of aliphatic polyamide and (B) weight average molecular weight Mw (B) of semi-aromatic polyamide]
The difference {Mw (A) −Mw (B)} between (A) the weight average molecular weight Mw (A) of the aliphatic polyamide and (B) the weight average molecular weight Mw (B) of the semi-aromatic polyamide is preferably 2000 or more, It is more preferably at least 5,000, more preferably at least 8,000, particularly preferably at least 10,000, most preferably at least 12,000.
When {Mw (A) -Mw (B)} is equal to or more than the above lower limit, (B) the semi-aromatic polyamide forms a micro-sized domain, and is a composition which is more excellent in water absorption rigidity and thermal rigidity. Can be.

[Molecular weight distribution of polyamide composition]
The molecular weight distribution of the polyamide composition of the present embodiment uses the 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, even more preferably 1.8, and 1.9. Particularly preferred.
On the other hand, the upper limit of Mw / Mn of the polyamide composition of this embodiment is preferably 2.6, more preferably 4, more preferably 2.3, particularly preferably 2.2, and most preferably 2.1.
That is, the Mw / Mn of the polyamide composition of the present embodiment is preferably 1.0 or more and 2.6 or less, more preferably 1.0 or more and 2.4 or less, still more preferably 1.7 or more and 2.4 or less. More preferably, it is 2.8 or more and 2.3 or less, particularly preferably 1.9 or more and 2.2 or less, most preferably 1.9 or more and 2.1 or less.
When Mw / Mn is in the above range, a polyamide composition having more excellent fluidity and the like tends to be obtained. Further, a molded article obtained from a polyamide composition containing a component represented by (C) an inorganic filler tends to be more excellent in surface appearance.

As a method of 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)) of semiaromatic polyamide / number average molecular weight ( And Mn (B)) in the range described below.
When an 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 ratio of polyamide molecules having a three-dimensional structure of the molecule can be further reduced, and the three-dimensional structure of the molecule can be more suitably prevented during high-temperature processing, and the fluidity can be improved. It can be kept better. Thereby, there is a tendency that the surface appearance of a molded product obtained from the polyamide composition containing the component represented by the inorganic filler (C) can be further improved.
The weight average molecular weight (Mw) / number average molecular weight (Mn) of the polyamide composition uses the weight average molecular weight (Mw) and the number average molecular weight (Mn) obtained by using GPC 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 220 ° C or higher and 270 ° C or lower, further preferably 230 ° C or higher and 265 ° C or lower, particularly preferably 240 ° C or higher and 260 ° C or lower, and more preferably 250 ° C or higher and 260 ° C or lower. Is most preferred.
When the melting point Tm2 of the polyamide composition is equal to or higher than the above lower limit, a polyamide composition which is more excellent in rigidity under heat and the like tends to be obtained.
On the other hand, when the melting point Tm2 of the polyamide composition is equal to or less than the above upper limit, thermal decomposition of the polyamide composition in melt processing such as extrusion and molding tends to be further suppressed.

[Enthalpy of crystallization ΔH of polyamide composition]
The crystallization enthalpy ΔH of the polyamide composition is preferably 10 J / g or more, more preferably 14 J / g or more, still more preferably 18 J / g or more, and preferably 20 J / g or more is particularly preferred. On the other hand, the upper limit of the crystallization enthalpy ΔH is not particularly limited, and a higher value is more preferable.
As a method of controlling the crystallization enthalpy ΔH of the polyamide composition within the above range, for example, a method of controlling the content of (A) an aliphatic polyamide and (B) a semi-aromatic polyamide to a range described later and the like can be mentioned. .
As a measuring device of the melting point Tm2 and crystallization enthalpy ΔH of the polyamide composition, for example, Diamond-DSC manufactured by PERKIN-ELMER and the like can be mentioned.

[Tan δ peak temperature of polyamide composition]
The lower limit of the tan δ peak temperature of the polyamide composition is 90 ° C, preferably 100 ° C, more preferably 110 ° C, and even more preferably 120 ° C. On the other hand, the upper limit of the tan δ peak temperature of the resin composition is preferably 150 ° C., more preferably 140 ° C., and even more preferably 130 ° C.
That is, the tan δ peak temperature of the resin composition is 90 ° C or higher, preferably 100 ° C or higher and 150 ° C or lower, more preferably 110 ° C or higher and 140 ° C or lower, and even more preferably 120 ° C or higher and 130 ° C or lower.
When the tan δ peak temperature of the polyamide composition is equal to or higher than the above lower limit, the polyamide composition tends to be more excellent in water absorption stiffness and stiffness when heated. On the other hand, when the tan δ peak temperature of the polyamide composition is equal to or less than the upper limit, a molded article obtained from the polyamide composition containing a component represented by the filler tends to have a more excellent surface appearance. is there.
As a method of controlling the tan δ peak temperature of the polyamide composition within the above range, for example, a method of controlling the content of (A) an aliphatic polyamide and (B) a semi-aromatic polyamide within a range described later and the like can be mentioned.

[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 240 ° C., more preferably from 170 ° C. to 230 ° C., and more preferably from 180 ° C. to 225 ° C. Is more preferably 190 ° C. or more and 220 ° C. or less, and most preferably 200 ° C. or more and 215 ° C.
When the crystallization peak temperature Tc (° C.) of the polyamide composition is equal to or higher than the lower limit, a polyamide composition having more excellent releasability during molding can be obtained.
On the other hand, when the crystallization peak temperature Tc (° C.) of the polyamide composition is equal to or less than the upper limit, the surface appearance of a molded article obtained from the polyamide composition containing (C) a component represented by the inorganic filler is obtained. Will be better.
The measurement of the melting point crystallization peak temperature Tc of the polyamide composition of the present embodiment can be performed according to JIS-K7121 by the method described in Examples described later.
As an apparatus for measuring the crystallization peak temperature Tc, for example, Diamond-DSC manufactured by PERKIN-ELMER and the like can be mentioned.
As a method of controlling the crystallization peak temperature Tc of the polyamide within the above range, for example, a method of controlling the content of the (A) aliphatic polyamide and (B) the semi-aromatic polyamide within the above-mentioned range can be mentioned.

[Amount of Blocked Terminal in Polyamide Composition]
The amount of the capped terminal in the polyamide composition is preferably 5 μeq / g or more and 180 μeq / g or less, more preferably 10 μeq / g or more and 170 μeq / g or less, and more preferably 20 μeq / g with respect to 1 g of the polyamide. It is more preferably 160 μe / g or less, more preferably 30 μe / g or more and 140 μe / g or less, most preferably 40 μe / g or more and 140 μe / g or less. When the amount of the capped end is in the above range, a composition having excellent MD, surface appearance, and heat strength at the time of molding can be obtained. The amount of capped terminals can be measured by NMR.

[Total amount of amino terminal amount and carboxyl terminal amount of polyamide composition]
The total amount of the amino terminal amount and the carboxyl terminal amount of the polyamide composition is preferably 70 μe / g or more and 145 μe / g, and more preferably 80 μe / g or more and 140 μe / g, based on 1 g of the semi-aromatic polyamide (B). The following is more preferable, 90 μe / g or more and 130 μe / g or less is further preferable, and 100 μe / g or more and 120 μe / g or less is particularly preferable.
When the total amount of the amino terminal and the carboxyl terminal of the polyamide composition is in the above range, a polyamide composition excellent in fluidity and the like can be obtained. Further, the surface appearance of a molded article obtained from a polyamide composition containing a component represented by an inorganic filler becomes more excellent.

[Ratio of amino all-in-one to total amount of amino terminal amount and carboxyl terminal amount of polyamide composition]
The ratio (amino terminal amount / (amino terminal amount + carboxy terminal amount)) of the total amount of amino to the total amount of the amino terminal amount and the carboxyl terminal amount of the polyamide composition is preferably 0.25 or more and less than 0.4. 0.35 or more and less than 0.4, more preferably 0.25 or more and less than 0.35. When the ratio of the amount of the amino terminal to the total amount of the amount of the amino terminal and the amount of the carboxyl terminal is not less than the lower limit, corrosion of the extruder or the molding machine can be more effectively suppressed. On the other hand, when the ratio of the amino terminal amount to the total amount of the amino terminal amount and the carboxyl terminal amount is less than the above upper limit, a composition excellent in discoloration to heat or light can be obtained.

The polyamide composition of the present embodiment having the above-described configuration can form a molded article having excellent water absorption rigidity, rigidity at heat, fluidity and corrosion resistance, and excellent surface appearance.
Hereinafter, the details of each component of the polyamide composition of the present embodiment will be described.

  Hereinafter, each component contained in the polyamide composition of the present embodiment will be described.

<(A) Aliphatic polyamide>
The (A) aliphatic polyamide contained in the polyamide composition of the present embodiment contains (Aa) an aliphatic dicarboxylic acid unit and (Ab) an aliphatic diamine unit.

[(A-a) aliphatic dicarboxylic acid unit]
Examples of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit include, but are not limited to, malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethyl Glutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaine Linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms such as acids, sebacic acid, dodecandioic acid, tetradecandioic acid, hexadecandioic acid, octadecandioic acid, eicosandioic acid, and diglycolic acid; Is mentioned.

(A-a) Since the aliphatic dicarboxylic acid unit tends to be more excellent in heat resistance, fluidity, toughness, low water absorption, rigidity and the like of the polyamide composition, an aliphatic having 6 to 20 carbon atoms. It preferably contains a dicarboxylic acid. The aliphatic dicarboxylic acid unit having a carbon number of 6 or more and 20 or less is not particularly limited. Is mentioned. Above all, adipic acid, sebacic acid or dodecane diacid is preferable from the viewpoint of heat resistance of the polyamide composition.
As the aliphatic dicarboxylic acid constituting the (A-a) aliphatic dicarboxylic acid unit, one type may be used alone, or two or more types may be used in combination.

  In addition, (A) the aliphatic polyamide may further include a unit derived from a trivalent or higher polyvalent carboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid, if necessary. The trivalent or higher polyvalent carboxylic acid may be used alone or in combination of two or more.

[(A-b) Aliphatic diamine unit]
(Ab) The aliphatic diamine constituting the aliphatic diamine unit may be linear or branched.
Examples of the linear aliphatic diamine constituting the aliphatic diamine unit include, but are not limited to, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, Examples thereof include linear saturated aliphatic diamines having 2 to 20 carbon atoms, such as methylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and tridecamethylene diamine.

The diamine constituting the diamine unit having a substituent branched from the main chain is not limited to the following, but for example, 2-methylpentamethylenediamine (also referred to as 2-methyl-1,5-diaminopentane). ), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also referred to as 2-methyloctamethylenediamine), 2,4- Examples thereof include a branched saturated aliphatic diamine having 3 to 20 carbon atoms such as dimethyloctamethylenediamine.
Among them, 2-methylpentamethylenediamine or 2-methyl-1,8-octanediamine is preferable, and 2-methylpentamethylenediamine is more preferable. When such an aliphatic diamine is contained, the polyamide composition tends to be more excellent in heat resistance, rigidity and the like.

  (Ab) The number of carbon atoms of the aliphatic diamine unit is preferably from 6 to 12, and more preferably from 6 to 10. When the number of carbon atoms is equal to or more than the lower limit, heat resistance is excellent, and when the number of carbons is equal to or less than the upper limit, crystallinity and mold releasability are excellent.

In addition, (Ab) the aliphatic diamine may further contain a trivalent or higher polyvalent aliphatic amine such as bishexamethylenetriamine, if necessary.
Diamines may be used alone or in combination of two or more.

  Specific examples of the aliphatic polyamide (A) used in the polyamide composition of the present embodiment include polyamide 66 (PA66), polyamide 46 (PA46), and polyamide 610 (PA610). PA66 is considered to be a material suitable for automotive parts because of its excellent heat resistance, moldability and toughness. A long-chain aliphatic polyamide such as PA610 has excellent chemical resistance.

In the polyamide composition of the present embodiment, the blending amount of the aliphatic polyamide (A) is 50.0 parts by mass or more and 99.0 parts by mass or less with respect to 100 parts by mass of the total amount of polyamide in the polyamide composition. It is preferably from 5.5 parts by mass to 95.0 parts by mass, more preferably from 54.0 parts by mass to 90.0 parts by mass, further preferably from 55.0 parts by mass to 85.0 parts by mass, and more preferably 56.0 parts by mass. The amount is more preferably from 5 parts by mass to 80.0 parts by mass, particularly preferably from 57.0 parts by mass to 77.5 parts by mass, and most preferably from 57.5 parts by mass to 75.5 parts by mass.
By setting the blending amount of the (A) aliphatic polyamide in the above range, a polyamide composition having excellent mechanical properties, particularly excellent rigidity in water absorption, rigidity at heat, fluidity, corrosion resistance, and the like can be obtained. Further, a polyamide composition containing a component represented by an inorganic filler has excellent surface appearance.

<(B) Semi-aromatic polyamide>
The (B) semi-aromatic polyamide contained in the polyamide composition of the present embodiment contains (Ba) a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and at least 50 diamine units having 4 to 10 carbon atoms. And (Bb) a diamine unit.
The total amount of the isophthalic acid unit and the diamine unit having 4 to 10 carbon atoms is preferably from 80 mol% to 100 mol%, more preferably 90 mol%, based on the total amount of all the structural units of the semiaromatic polyamide (B). It is more preferably at least 100 mol%, and further preferably 100 mol%.
In the present invention, the proportion of the predetermined monomer units constituting the semiaromatic polyamide (B) can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[(Ba) dicarboxylic acid unit]
(Ba) In the dicarboxylic acid unit, the content of the isophthalic acid unit with respect to the total amount of the dicarboxylic acid is 75 mol% or more, preferably 80 mol% or more and 100 mol% or less, and 90 mol% or more and 100 mol% or less. More preferably, 100 mol% is still more preferable.
When the content of the isophthalic acid unit with respect to the total number of moles of the dicarboxylic acid is equal to or more than the lower limit, mechanical properties, particularly, water absorption rigidity, rigidity at heat, fluidity, surface appearance, corrosion resistance, and the like are simultaneously satisfied. , A polyamide composition can be obtained.

  The (Ba) dicarboxylic unit may contain an aromatic dicarboxylic acid unit, an aliphatic dicarboxylic acid unit, or an alicyclic dicarboxylic acid unit other than the isophthalic acid unit.

(Aromatic dicarboxylic acid unit)
Examples of the aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit other than the isophthalic acid unit include, but are not limited to, a dicarboxylic acid having a phenyl group and a naphthyl group. The aromatic group of the aromatic dicarboxylic acid may be unsubstituted or may have a substituent.
Examples of the substituent include, but are not particularly limited to, 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 chloro group, and a bromo group. Halogen group, a silyl group having 1 to 6 carbon atoms, a sulfonic acid group and a salt thereof (such as a sodium salt).
Specifically, although not limited to the following, unsubstituted terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, etc. Alternatively, an aromatic dicarboxylic acid having 8 to 20 carbon atoms and substituted with a predetermined substituent may, for example, be mentioned. Among them, terephthalic acid is preferred.
As the aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit, only one kind may be used alone, or two or more kinds may be used in combination.

(Aliphatic dicarboxylic acid unit)
Examples of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit include, but are not limited to, malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethyl Glutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaine Linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms such as acids, sebacic acid, dodecandioic acid, tetradecandioic acid, hexadecandioic acid, octadecandioic acid, eicosandioic acid, and diglycolic acid; Is mentioned.

(Alicyclic dicarboxylic acid unit)
The alicyclic dicarboxylic acid constituting the alicyclic dicarboxylic acid unit (hereinafter, also referred to as “alicyclic dicarboxylic acid unit”) is not limited to the following. An alicyclic dicarboxylic acid having 3 to 10 or less is preferable, and an alicyclic dicarboxylic acid having an alicyclic structure having 5 to 10 carbon atoms is preferable.
Examples of such alicyclic dicarboxylic acids include, but are not limited to, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. No. Among them, 1,4-cyclohexanedicarboxylic acid is preferred.
The alicyclic dicarboxylic acid constituting the alicyclic dicarboxylic acid unit may be used alone or in combination of two or more.

The alicyclic group of the alicyclic dicarboxylic acid may be unsubstituted or have a substituent. Examples of the substituent include, but are not limited to, those having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. Examples include the following alkyl groups.
The dicarboxylic acid unit other than the isophthalic acid unit preferably contains an aromatic dicarboxylic acid unit, and more preferably contains an aromatic dicarboxylic acid having 6 to 12 carbon atoms.
By using such a dicarboxylic acid, the mechanical properties of the polyamide composition, particularly the rigidity of water absorption, the rigidity at heat, the fluidity, the surface appearance, the corrosion resistance, and the like tend to be more excellent.

In the polyamide composition of the present embodiment, the dicarboxylic acid constituting the (Ba) dicarboxylic acid unit is not limited to the compound described as the dicarboxylic acid, and may be a compound equivalent to the dicarboxylic acid. Is also good.
Here, the “compound equivalent to a dicarboxylic acid” refers to 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, anhydrides and halides of dicarboxylic acids.

In addition, (B) the semi-aromatic polyamide may further include a unit derived from a trivalent or higher polycarboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid, if necessary.
The trivalent or higher polycarboxylic acid may be used alone or in combination of two or more.

[(Bb) diamine unit]
(B) The diamine unit (Bb) constituting the semi-aromatic polyamide contains at least 50 mol% of a diamine unit having 4 to 10 carbon atoms. Although not limited to the following, for example, an aliphatic diamine unit, an alicyclic diamine unit, an aromatic diamine unit and the like can be mentioned.

(Aliphatic diamine unit)
Examples of the aliphatic diamine constituting the aliphatic diamine unit include, but are not limited to, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, Examples thereof include linear saturated aliphatic diamines having 2 to 20 carbon atoms, such as nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

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

(Aromatic diamine unit)
The aromatic diamine constituting the aromatic diamine unit is not limited to the following as long as it is an aromatic-containing diamine, and examples thereof include meta-xylylenediamine.

Among them, an aliphatic diamine unit is preferable, a diamine unit having a linear saturated aliphatic group having 4 to 10 carbon atoms is more preferable, and a diamine unit having a linear saturated aliphatic group having 6 to 10 carbon atoms is preferable. Even more preferred is a hexamethylenediamine unit.
By using such a diamine, there is a tendency that the polyamide composition is more excellent in mechanical properties, in particular, rigidity of water absorption, rigidity at heat, fluidity, surface appearance, corrosiveness and the like.
The diamines may be used alone or in a combination of two or more.

  As the semi-aromatic polyamide (B), polyamides 6I, 9I, and 10I are preferred, and polyamide 6I is particularly preferred.

In addition, (B) the semi-aromatic polyamide may further include a trivalent or higher polyvalent aliphatic amine such as bishexamethylene triamine, if necessary.
The trivalent or higher polyvalent aliphatic amine may be used alone or in combination of two or more.

  In the polyamide composition of the present embodiment, the blending amount of the semi-aromatic polyamide (B) is 1.0 part by mass or more and 50.0 parts by mass or less based on 100 parts by mass of the total polyamide in the polyamide composition. It is preferably from 5.0 parts by mass to 47.5 parts by mass, more preferably from 10.0 parts by mass to 46.0 parts by mass, further preferably from 15.0 parts by mass to 45.0 parts by mass, and more preferably 20.0 parts by mass or less. The amount is more preferably from 4 parts by mass to 44.0 parts by mass, particularly preferably from 22.5 parts by mass to 43.0 parts by mass, and most preferably from 24.5 parts by mass to 42.5 parts by mass. By setting the blending amount of the semi-aromatic polyamide (B) in the above range, a polyamide composition having excellent mechanical properties, particularly, rigidity of water absorption, rigidity at heat, fluidity, corrosion resistance, and the like can be obtained. Further, a polyamide composition containing a component represented by an inorganic filler has excellent surface appearance.

[At least one unit selected from the group consisting of lactam units and aminocarboxylic acid units]
(A) The aliphatic polyamide and (B) the semi-aromatic polyamide may further contain at least one unit selected from the group consisting of lactam units and aminocarboxylic acid units. By including such a unit, a polyamide having more excellent toughness tends to be obtained. Here, the lactam and aminocarboxylic acid constituting the lactam unit and the aminocarboxylic acid refer to lactam and aminocarboxylic acid which can be polymerized (condensed).

  The lactam and aminocarboxylic acid constituting the lactam unit and aminocarboxylic acid unit are not limited to the following, but for example, lactam and aminocarboxylic acid having 4 to 14 carbon atoms are preferable, and 6 to 12 carbon atoms are preferable. The following lactams and aminocarboxylic acids are more preferred.

Examples of the lactam constituting the lactam unit include, but are not limited to, butyrolactam, pivalolactam, ε-caprolactam, capryloractam, enantholactam, undecanolactam, laurolactam (dodecanolactam), and the like. Can be
Among them, as the lactam, ε-caprolactam or laurolactam is preferable, and ε-caprolactam is more preferable. By containing such a lactam, the polyamide composition tends to be more excellent in toughness.

Examples of the aminocarboxylic acid constituting the aminocarboxylic acid unit include, but are not limited to, ω-aminocarboxylic acids and α, ω-amino acids which are compounds in which a lactam is opened.
As the aminocarboxylic acid, 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. Such aminocarboxylic acids are not limited to the following, but include, for example, 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like. In addition, examples of the aminocarboxylic acid include para-aminomethylbenzoic acid.

  The lactam and aminocarboxylic acid constituting the lactam unit and the aminocarboxylic acid unit may be used alone or in combination of two or more.

The total ratio (mol%) of the lactam unit and the aminocarboxylic acid unit is preferably from 0 mol% to 20 mol%, more preferably from 0 mol% to 10 mol%, and more preferably from 0 mol% to 5 mol%, based on the entire polyamide. More preferably, it is at most mol%.
When the total ratio of the lactam unit and the aminocarboxylic acid unit is in the above range, effects such as improvement in fluidity tend to be obtained.

<Terminal sealant>
At least one polyamide selected from the group consisting of (A) an aliphatic polyamide and (B) a semi-aromatic polyamide contained in the polyamide composition of the present embodiment has a terminal blocked by a terminal blocking agent.
Such a terminal blocking agent, the above-mentioned dicarboxylic acid and diamine, and optionally used, at least one compound selected from the group consisting of lactam and aminocarboxylic acid, when producing polyamide, It can also be added as a molecular weight regulator.

Examples of the terminal blocking agent include, but are not limited to, acid anhydrides, monoisocyanates, monoacid halides, monoesters, and monoalcohols. Examples of the acid anhydride include a monocarboxylic acid, a monoamine, and phthalic anhydride.
Among them, monocarboxylic acids and monoamines are preferred. When the terminal of the polyamide is blocked by the terminal blocking agent, the polyamide composition tends to be more excellent in thermal stability.
One type of terminal blocking agent may be used alone, or two or more types may be used in combination.

The monocarboxylic acid that can be used as the terminal blocking agent may be any one having reactivity with an amino group that may be present at the terminal of the polyamide. Specific examples of the monocarboxylic acid include, but are not limited to, aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids.
Examples of the aliphatic monocarboxylic acid include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristyl acid, palmitic acid, Stearic acid, pivalic acid, isobutylic acid and the like can be mentioned.
The alicyclic monocarboxylic acid is not limited to the following, but examples include cyclohexanecarboxylic acid.
Examples of the aromatic monocarboxylic acid include, but are not limited to, benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid.
These monocarboxylic acids may be used alone or in a combination of two or more.

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

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

<Production method of polyamide>
When obtaining each polyamide, it is preferable that the addition amount of the dicarboxylic acid and the addition amount of the diamine are around the same molar amount. The molar amount of the entire dicarboxylic acid is preferably 0.9 or more and 1.2 or less with respect to the molar amount of the entire dicarboxylic acid of 1, taking into consideration the amount of the diamine that escapes from the reaction system during the polymerization reaction in the molar ratio. , 0.95 or more and 1.1 or less, more preferably 0.98 or more and 1.05 or less.

The method for producing the 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 polymerizing at least one member selected from the group consisting of a lactam constituting a lactam unit and an aminocarboxylic acid constituting an aminocarboxylic acid unit to obtain a polymer;

  The method for producing a polyamide preferably further includes, after the polymerization step, a step of increasing the degree of polymerization of the polyamide. Further, if necessary, a sealing step of sealing the terminal of the obtained polymer with a terminal blocking agent may be included after the polymerization step and the raising step.

Specific methods for producing polyamide include, for example, various methods as exemplified in the following 1) to 4).
1) One or more aqueous solutions or aqueous 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 a molten state (Hereinafter, may be referred to as “hot melt polymerization method”).
2) A method of increasing the degree of polymerization while maintaining the solid state of the polyamide obtained by the hot melt polymerization method at a temperature equal to or lower than the melting point (hereinafter, may be referred to as "hot melt polymerization / solid state 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”). Legally ").
4) A method of polymerizing using a dicarboxylic acid halide component equivalent to a dicarboxylic acid and a diamine component (hereinafter, may be referred to as a "solution method").

Above all, as a specific method for producing a polyamide, a production method including a hot melt polymerization method is preferable. Further, when producing a polyamide by a hot melt polymerization method, it is preferable to maintain a molten state until the polymerization is completed. In order to maintain the molten state, it is necessary to produce the polyamide under polymerization conditions suitable for the polyamide. 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 reduced while applying pressure for 30 minutes or more until the pressure in the tank becomes atmospheric pressure (gauge pressure is 0 kg / cm ² ).

In the method for producing a 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, and an extruder reactor (such as a kneader).

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

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

<Characteristics of polyamide>
[(A) Characteristics of aliphatic polyamide]
(A) The molecular weight of the aliphatic polyamide, the amount of the capped terminal, the melting point Tm2, the crystallization enthalpy ΔH, and the tan δ peak temperature can be configured as follows, and are specifically measured by the following method. be able to.

((A) Weight average molecular weight Mw (A) of aliphatic polyamide)
(A) As an index of the molecular weight of the aliphatic polyamide, a weight average molecular weight can be used. (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 20,000 to 40,000, and particularly preferably from 25,000 to 35,000.
When the Mw (A) is in the above range, a polyamide composition which can simultaneously satisfy mechanical properties, particularly, water absorption rigidity, heat rigidity, fluidity, corrosion resistance and the like tends to be obtained. Further, a molded article obtained from a polyamide composition containing a component typified by an inorganic filler has a more excellent surface appearance.
The weight average molecular weight (Mw (A)) of the aliphatic polyamide (A) can be measured using GPC.

((A) Molecular weight distribution of aliphatic polyamide)
The molecular weight distribution of the (A) aliphatic polyamide is represented by (A) the weight average molecular weight (Mw (A)) of the aliphatic polyamide / (A) the number average molecular weight (Mn (A)) of the aliphatic polyamide.
Mw (A) / Mn (A) is preferably 1.0 or more, more preferably 1.8 or more and 2.2 or less, and still more preferably 1.9 or more and 2.1 or less.
When Mw (A) / Mn (A) is in the above range, a polyamide composition having excellent fluidity and the like can be obtained. Further, a molded article obtained from a polyamide composition containing a component typified by an inorganic filler has a more excellent surface appearance.

As a method of controlling Mw (A) / Mn (A) within the above range, for example, the following method 1) or 2) can be mentioned.
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 method of the above 1), a method of controlling polymerization conditions such as heating conditions and reduced pressure conditions.

  Note that Mw (A) / Mn (A) can be calculated using Mw (A) and Mn (A) obtained using GPC.

((A) Amount of Terminal Blocked of Aliphatic Polyamide)
(A) The amount of the capped terminal of the aliphatic polyamide is preferably 5 μequivalent / g or more and 180 μequivalent / g or less, and preferably 5 μequivalent / g or more and 150 μequivalent / g or less based on 1 g of the aliphatic polyamide (A). More preferably, it is 10 μe / g or more and 100 μe / g or less, particularly preferably 15 μe / g or more and 80 μe / g or less, most preferably 20 μe / g or more and 60 μe / g or less. When the amount of the capped end is in the above range, a composition having excellent MD, surface appearance, and heat strength at the time of molding can be obtained. The amount of capped terminals can be measured by NMR.

((A) Melting point Tm2 of aliphatic polyamide)
(A) The lower limit of the melting point Tm2 of the aliphatic polyamide is preferably 220 ° C, more preferably 230 ° C, and still more preferably 240 ° C. On the other hand, the upper limit of the melting point Tm2 of the aliphatic polyamide (A) is preferably 300 ° C, more preferably 290 ° C, further preferably 280 ° C, and particularly preferably 270 ° C.
That is, the melting point Tm2 of the aliphatic polyamide (A) is preferably from 220 ° C to 300 ° C, more preferably from 230 ° C to 290 ° C, further preferably from 240 ° C to 280 ° C, particularly preferably from 240 ° C to 270 ° C. preferable.
(A) When the melting point Tm2 of the aliphatic polyamide is equal to or higher than the above lower limit, the molded article obtained from the polyamide composition tends to have higher rigidity at heat and the like. On the other hand, when the melting point Tm2 of the aliphatic polyamide (A) is equal to or less than the above upper limit, thermal decomposition or the like of the polyamide composition in melt processing such as extrusion and molding tends to be further suppressed.

((A) Enthalpy of crystallization ΔH of aliphatic polyamide)
(A) The lower limit of the crystallization enthalpy ΔH of the aliphatic polyamide is preferably 30 J / g, more preferably 40 J / g, and still more preferably 50 J / g, from the viewpoint of mechanical properties, in particular, water absorption rigidity and rigidity at the time of heating. 60 J / g is particularly preferred. On the other hand, the upper limit of the crystallization enthalpy ΔH of the aliphatic polyamide (A) is not particularly limited, and the higher the higher, the better.
(A) As an apparatus for measuring the melting point Tm2 and crystallization enthalpy ΔH of the aliphatic polyamide, for example, Diamond-DSC manufactured by PERKIN-ELMER and the like can be mentioned.

((A) Tan δ peak temperature of aliphatic polyamide)
(A) The tan δ peak temperature of the aliphatic polyamide is preferably 40 ° C or higher, more preferably 50 ° C or higher and 110 ° C or lower, further preferably 60 ° C or higher and 100 ° C or lower, particularly preferably 70 ° C or higher and 95 ° C or lower, and 80 ° C. The temperature is more preferably at least 90 ° C.
(A) When the tan δ peak temperature of the aliphatic polyamide is equal to or higher than the lower limit, the molded article obtained from the polyamide composition tends to have more excellent water absorption rigidity and hot rigidity.
(A) The tan δ peak temperature of the aliphatic polyamide can be measured using a viscoelasticity measurement analyzer or the like (manufactured by Rheology: DVE-V4).

[(B) Characteristics of semi-aromatic polyamide]
(B) The molecular weight, melting point Tm2, crystallization enthalpy ΔH, tan δ peak temperature, sealed terminal amount, amino terminal amount, and carboxy terminal amount of the semi-aromatic polyamide can be configured as follows. It can be measured by the following method.

((B) Weight average molecular weight Mw (B) of semi-aromatic polyamide)
As an index of the molecular weight of the (B) 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 35,000 or less, more preferably 10,000 or more and 25,000 or less, further preferably 13,000 or more and 24,000 or less, and still more preferably 15,000 or more and 23,000 or less. , 18000 or more and 22,000 or less, particularly preferably 19,000 or more and 21,000 or less.
(B) When the weight average molecular weight (Mw (B)) of the semi-aromatic polyamide is in the above range, a polyamide composition having excellent mechanical properties, particularly excellent water absorption stiffness, stiffness when heated, fluidity, and the like can be obtained. Further, a molded article obtained from a polyamide composition containing a component typified by an inorganic filler has a more excellent surface appearance.
The weight average molecular weight (Mw (B)) of the semi-aromatic polyamide (B) can be measured using GPC.

((B) Molecular weight distribution of semi-aromatic polyamide)
The molecular weight distribution of (B) the semi-aromatic polyamide is represented by the weight average molecular weight (Mw (B)) of the (B) semi-aromatic polyamide / the number average molecular weight (Mn (B)) of the semi-aromatic polyamide. I do.
Mw (B) / Mn (B) is preferably 1.0 or more and 2.6 or less, more preferably 1.0 or more and 2.4 or less, still more preferably 1.7 or more and 2.4 or less. 0.3 or less is still more preferable, 1.9 or more and 2.2 or less are particularly preferable, and 1.9 or more and 2.1 or less are most preferable.
When Mw (B) / Mn (B) is in the above range, a polyamide composition having more excellent fluidity and the like can be obtained. Further, a molded article obtained from a polyamide composition containing a component typified by an inorganic filler has a more excellent surface appearance.

As a method for controlling Mw (B) / Mn (B) within the above range, for example, the following methods 1) and 2) can be mentioned.
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 method of the above 1), a method in which polymerization conditions such as heating conditions and reduced pressure conditions are controlled to complete the polycondensation reaction at a temperature as low as possible and in a short time.

In particular, if the semi-aromatic polyamide (B) is an amorphous polyamide, it does not have a melting point, so that 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. A high molecular weight distribution indicates a high proportion of polyamide molecules having a three-dimensional molecular structure. Therefore, by controlling Mw (B) / Mn (B) within the above range, the progress of three-dimensional structuring of molecules during high-temperature processing can be suppressed, and a polyamide composition excellent in fluidity and the like can be obtained. Further, the surface appearance of a molded article obtained from a polyamide composition containing a component represented by an inorganic filler becomes more excellent.
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, and still 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 preferred.
(B) The method of controlling the crystallization enthalpy ΔH of the semi-aromatic polyamide within the above range can be a known method of reducing the crystallinity of the polyamide, and is not particularly limited. As a method of reducing the crystallinity of a known polyamide, specifically, for example, a method of increasing the ratio of meta-substituted aromatic dicarboxylic acid units to dicarboxylic acid units, and a ratio of meta-substituted aromatic diamine units to diamine units There is a method of enhancing. From this viewpoint, it is important that the (B) semi-aromatic polyamide contains, as the (Ba) dicarboxylic acid unit, 75 mol% of the isophthalic acid unit in all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide. And it is particularly preferable to contain 100 mol%.
(B) Examples of a device for measuring the crystallization enthalpy ΔH of the semi-aromatic polyamide include Diamond-DSC manufactured by PERKIN-ELMER.

((B) tan δ peak temperature of semi-aromatic polyamide)
(B) The tan δ peak temperature of the semi-aromatic polyamide is preferably 90 ° C or higher, more preferably 100 ° C or higher and 160 ° C or lower, further preferably 110 ° C or higher and 150 ° C or lower, particularly preferably 120 ° C or higher and 145 ° C or lower, and 130 ° C or lower. The temperature is most preferably 140 ° C or higher and 140 ° C or lower.
(B) When the tan δ peak temperature of the semi-aromatic polyamide is equal to or higher than the lower limit, a polyamide composition having more excellent water absorption rigidity and hot rigidity tends to be obtained. When the tan δ peak temperature of the polyamide composition is equal to or less than the upper limit, the surface appearance of a molded article obtained from the polyamide composition containing a component represented by the inorganic filler becomes more excellent.
(B) As a method of controlling the tan δ peak temperature of the semi-aromatic polyamide within the above range, for example, a method of increasing the ratio of an aromatic monomer to a dicarboxylic acid unit and the like can be mentioned. From this viewpoint, it is important that the (B) semi-aromatic polyamide contains, as the (Ba) dicarboxylic acid unit, 75 mol% of the isophthalic acid unit in all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide. And it is particularly preferable to contain 100 mol%.
(B) The tan δ peak temperature of the semi-aromatic polyamide can be measured using, for example, a viscoelasticity measurement analyzer (manufactured by Rheology: DVE-V4).

((B) the amount of the capped terminal of the semi-aromatic polyamide)
The amount of the capped terminal of the (B) semi-aromatic polyamide is preferably from 5 μe / g to 180 μe / g, and more preferably from 10 μe / g to 170 μe / g, based on 1 g of the semi-aromatic polyamide (B). The following is more preferred, the equivalent is 30 μe / g or more and 160 μe / g or less, particularly preferably 50 μe / g or more and 160 μe / g or less, and most preferably 60 μe / g or more and 160 μe / g or less. When the amount of the capped end is in the above range, a composition having excellent MD, surface appearance, and heat strength at the time of molding can be obtained. Further, it is particularly preferable that the amount of the terminal capped with acetic acid is within the above range. The amount of capped terminals can be measured by NMR.

((B) Amino terminal amount of semi-aromatic polyamide)
The amino terminal amount of the (B) semi-aromatic polyamide is preferably from 5 μe / g to 90 μe / g, more preferably from 10 μe / g to 80 μe / g, based on 1 g of the (A) semi-aromatic polyamide. The equivalent is more preferably 10 μe / g or more and 70 μe / g or less, particularly preferably 20 μe / g or more and 60 μe / g or less, and most preferably 30 μe / g or more and 50 μe / g or less.
(B) When the amino terminal amount of the semi-aromatic polyamide is within the above range, a polyamide composition which is more excellent in discoloration to heat and light can be obtained.
In addition, the amino terminal amount can be measured by NMR.

((B) Carboxyl terminal amount of semi-aromatic polyamide)
The carboxyl terminal amount of the (B) semi-aromatic polyamide is preferably from 20 μe / g to 150 μe / g, more preferably from 30 μe / g to 120 μe / g, based on 1 g of the (A) semi-aromatic polyamide. Preferably, it is 30 μe / g or more and 100 μe / g or less, particularly preferably 40 μe / g or more and 90 μe / g or less, most preferably 50 μe / g or more and 80 μe / g or less.
(B) When the carboxyl terminal amount of the semi-aromatic polyamide is in the above range, a polyamide composition having more excellent fluidity and the like can be obtained. Further, the surface appearance of a molded article obtained from a polyamide composition containing a component represented by an inorganic filler becomes more excellent.
In addition, the carboxyl terminal amount can be measured by NMR.

((B) Total amount of amino terminal amount and carboxyl terminal amount of semi-aromatic polyamide)
(B) The total amount of the amino terminal amount and the carboxyl terminal amount of the semi-aromatic polyamide is preferably from 50 µe / g to 155 µe / g, more preferably 60 µe / g, based on 1 g of the (B) semi-aromatic polyamide. The equivalent is more preferably 150 μe / g or less, more preferably 70 μe / g or more and 140 μe / g or less, particularly preferably 80 μe / g or more and 130 μe / g or less, and most preferably 90 μe / g or more and 120 μe / g or less. .
(B) When the total amount of the amino terminal and the carboxyl terminal of the semi-aromatic polyamide is within the above range, a polyamide composition having more excellent fluidity and the like can be obtained. Further, the surface appearance of a molded article obtained from a polyamide composition containing a component represented by an inorganic filler becomes more excellent.

<Other components>
The polyamide composition of the present embodiment comprises (C) an inorganic filler, (D) a nucleating agent, (E) a lubricant, (F) in addition to (A) the aliphatic polyamide and (B) the semi-aromatic polyamide. A) heat stabilizer, (G) another polymer, (H) at least one metal salt selected from the group consisting of metal phosphites and metal hypophosphites, (J) a phosphite compound, and , (K) and one or more other components selected from the group consisting of other additives.

[(C) inorganic filler]
(C) Examples of the inorganic filler include, but are not limited to, 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, calcium fluoride, montmorillonite, Junsei fluorine mica, apatite, and the like. One type of these (C) inorganic fillers may be used alone, or two or more types may be used in combination.
Among them, from the viewpoint of further improving the mechanical strength, from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fiber, aluminum borate fiber and clay One or more selected are preferred. Among them, one or more selected from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate and clay are more preferable.

(C) When the inorganic filler is glass fiber or carbon fiber, the number average fiber diameter (d) is preferably 3 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, still more preferably 3 μm or more and 12 μm or less, and more preferably 3 μm or more and 9 μm. The following is particularly preferable, and the range of 4 μm or more and 6 μm or less is most preferable.
By setting the number average fiber diameter to the upper limit or less, a polyamide composition having more excellent toughness and surface appearance of a molded product can be obtained. On the other hand, when the number average fiber diameter is equal to or more than the above lower limit, a polyamide composition having an excellent balance between cost, powder handling and physical properties (eg, fluidity) can be obtained. Further, by setting the number average fiber diameter to 3 μm or more and 9 μm or less, it is possible to obtain a polyamide composition having excellent vibration fatigue properties and slidability.

  (C) When the inorganic filler is glass fiber or carbon fiber, its cross section may be a perfect circle or a flat shape. The flat cross section is not limited to the following, but includes, for example, a rectangle, an ellipse close to a rectangle, an ellipse, and a cocoon shape with a narrowed central portion in the longitudinal direction. Here, the “flatness” in this specification refers to 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 (a perfect circle is a flat circle). The rate is about 1).

  (C) When the inorganic filler is a glass fiber or a carbon fiber, the number average fiber diameter (d) is 3 μm or more and 30 μm or less, from the viewpoint that excellent mechanical strength can be imparted to the polyamide composition. The fiber length (l) is 100 μm or more and 750 μm or less, and the ratio of the number average fiber diameter (d) to the weight average fiber length (l), that is, the aspect ratio (l / d) is 10 or more and 100 or less. Is preferred. Here, the “number average fiber diameter (d)” is an average value of the major diameters of the fiber cross sections (the above d2), and is determined by using a calculation method described later.

  In addition, from the viewpoint of reducing the warpage of the plate-like molded product 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 or more. The following is more preferable, 2.5 or more and 10.0 or less are more preferable, more than 3.0 and 6.0 or less are especially preferable, and 3.1 or more and 6.0 or less are the most preferable. When the oblateness is within the above range, during the treatment of mixing, kneading or molding with other components, crushing can be more effectively prevented, and the desired effect for the molded article can be more sufficiently obtained. become.

  The thickness of the glass fiber or carbon fiber having an oblateness of 1.5 or more is not limited to the following, but the minor diameter d1 of the fiber cross section is 0.5 μm or more and 25 μm or less, and the major diameter d2 of the fiber cross section is 1.25 μm or more. Preferably it is 250 μm or less. More preferably, the minor diameter d1 of the fiber cross section is 3.0 μm or more and 25 μm or less, and the major diameter d2 of the fiber cross section is 1.25 μm or more and 250 μm or less. When the short diameter (d1) and the long diameter (d2) are within the above ranges, the difficulty of fiber spinning can be more effectively avoided, and the strength of the molded article can be reduced without reducing the contact area with the resin (polyamide). Can be further improved.

  Glass fibers and carbon fibers having an oblateness of 1.5 or more can be produced by using the methods described in Patent Documents 4 to 6, for example. In particular, in an orifice plate having a large number of orifices on the bottom surface, an orifice plate surrounding a plurality of orifice outlets and having a convex edge extending below the bottom surface, or an outer peripheral portion of a nozzle tip having one or more orifice holes A glass fiber having an aspect ratio of 1.5 or more, which is manufactured using any one of the nozzle tips for spinning a glass fiber having an irregular cross section provided with a plurality of convex edges extending downward from the front end, is preferable. These fibrous reinforcements may use the fiber strand as roving as it is, or may obtain a cutting step and use it as a chopped glass strand.

  Further, the “number average fiber diameter (d)” and “weight average fiber length (l)” in the present specification can be obtained by the following method. First, the polyamide composition is placed in an electric furnace, and the contained organic matter is incinerated. From the residue after the treatment, 100 or more glass fibers (or carbon fibers) are arbitrarily selected, observed with a scanning electron microscope (SEM), and the fiber diameter (major diameter) of these glass fibers (or carbon fibers) is determined. ), The number average fiber diameter can be determined. In addition, the weight average fiber length can be determined by measuring the fiber length using an SEM photograph of 100 or more glass fibers (or carbon fibers) taken at a magnification of 1000 times.

Further, the glass fiber or the 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, aminosilanes, mercaptosilanes, epoxysilanes, and vinylsilanes.
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.
One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.
Among them, aminosilanes are preferable as the silane coupling agent.

Further, the glass fiber or the carbon fiber may further contain a sizing agent.
As the sizing agent, for example, a copolymer containing a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer as a structural unit, an epoxy compound , A polyurethane resin, a homopolymer of acrylic acid, a copolymer 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 obtained polyamide composition, as a sizing agent, an unsaturated vinyl monomer other than the carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated vinyl monomer And at least one selected from the group consisting of a copolymer containing a polymer as a structural unit, an epoxy compound, and a polyurethane resin. Also, selected from the group consisting of a copolymer containing a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer as constituent units, and a polyurethane resin. One or more types are more preferable.

The glass fiber or 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 a known manufacturing process of the fiber. It is obtained by reacting in a suitable manner.
The fiber strands may be used as rovings as they are, or may be used as chopped glass strands after a further cutting step.
The sizing agent preferably gives (adds) about 0.2% by mass or more and 3% by mass or less as a solid content relative to the total mass of glass fibers or carbon fibers, and 0.3% by mass or more and 2% by mass. It is more preferable to add (add) the following degree.
When the amount of the sizing agent added is not less than the lower limit as the solid content relative to the total mass of the glass fibers or carbon fibers, the sizing of the fibers 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 the solid content relative to the total mass of the glass fibers or carbon fibers, the heat stability of the obtained polyamide composition is further improved.
The drying of the strand may be performed after the cutting step, or the strand may be dried and then cut.

  Inorganic fillers other than glass fibers and carbon fibers include wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fibers, and borate from the viewpoint of improving the strength, rigidity and surface appearance of molded articles. Aluminum acid fibers or clays are preferred. Wollastonite, kaolin, mica, talc, calcium carbonate or clay is more preferred. Wollastonite, kaolin, mica or talc are more preferred. Wollastonite, mica or talc are particularly preferred. These inorganic fillers may be used alone or in a combination of two or more.

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 surface appearance of the molded article. 0.05 μm or more and 25 μm or less, further preferably 0.10 μm or more and 20 μm or less, and particularly preferably 0.15 μm or more and 15 μm or less.
By setting the average particle size of the inorganic filler other than the glass fiber and the carbon fiber to the above upper limit value or less, a polyamide composition having more excellent toughness and surface appearance of a molded product can be obtained. On the other hand, when the average particle size is equal to or more than the lower limit, a polyamide composition having an excellent balance between cost, powder handling, and physical properties (eg, fluidity) can be obtained.

  Regarding needle-like inorganic fillers such as wollastonite 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 defined as (number average) fiber diameter.

  Regarding the number average particle length of the acicular inorganic filler (hereinafter, may be simply referred to as “average particle length”), the preferred range of the number average particle diameter described above, and the following number average particle diameter (d) The numerical range calculated from the preferable range of the aspect ratio (l / d) of the number average particle length (l) with respect to is preferable.

  Although having an acicular 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 article and improves the appearance of an injection molding machine or the like. From the viewpoint of preventing abrasion of the metallic parts, it is preferably 1.5 or more and 10 or less, more preferably 2.0 or more and 5 or less, and even more preferably 2.5 or more and 4 or less.

The inorganic filler other than the glass fiber and the carbon fiber may be subjected to a surface treatment using a silane coupling agent, a titanate coupling agent, or the like.
Examples of the silane coupling agent include those similar to those exemplified for the glass fiber and the carbon fiber.
Among them, aminosilanes are preferable as the silane coupling agent.
Such a surface treatment 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. Further, the addition amount of the surface treatment agent is preferably from 0.05% by mass to 1.5% by mass with respect to the total mass of the inorganic filler.

(C) The content of the inorganic filler is preferably from 5 parts by mass to 250 parts by mass, and more preferably from 30 parts by mass to 250 parts by mass, based on 100 parts by mass of the total of (A) the aliphatic polyamide and (B) the semiaromatic amide. It is more preferably at most 50 parts by mass and at most 240 parts by mass, particularly preferably at least 50 parts by mass and at most 200 parts by mass, most preferably at least 50 parts by mass and at most 150 parts by mass.
By setting the content of (C) the inorganic filler to the total of 100 parts by mass of the (A) polyamide resin pellets and the (B) crystalline amide, the lower limit or more, the strength and strength of the obtained polyamide composition are improved. The effect of improving the rigidity is exhibited. On the other hand, by setting the content of (C) the inorganic filler to 100 parts by mass in total of (A) the polyamide resin pellet and (B) the crystalline amide, the content is not more than the above upper limit, so that the extrudability and the moldability are improved. An excellent polyamide composition can be obtained.

[(D) Nucleating agent]
(D) The nucleating agent means a substance that can provide 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 making the spherulite of the obtained molded product fine or uniform in size.

(D) The nucleating agent is not limited to the following, but examples thereof include talc, boron nitride, mica, kaolin, silicon nitride, carbon black, potassium titanate, and molybdenum disulfide.
As the nucleating agent (D), only one type may be used alone, or two or more types may be used in combination.
Above all, as the nucleating agent (D), talc or boron nitride is preferable from the viewpoint of the nucleating agent effect.

In addition, 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 size of the nucleating agent can be measured using the following method. First, the molded article 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. Then, it can be determined by observing with an optical microscope, a scanning electron microscope or the like, and measuring the particle size.

The content of the nucleating agent in the polyamide composition of the present embodiment is 0.001 to 1 part by mass based on 100 parts by mass of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide). The content is preferably from 0.001 to 0.5 parts by mass, more preferably from 0.001 to 0.09 parts by mass.
By setting the content of the nucleating agent to 100 parts by mass or more of the polyamide and the lower limit or more, the heat resistance of the polyamide composition tends to be further improved. By setting the content to 100 parts by mass or less, the polyamide composition having more excellent toughness can be obtained.

(E) Lubricant The (E) lubricant 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. The lubricant (E) can also be used as a molding improver.

(Higher fatty acids)
Examples of the higher fatty acid 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.
Among them, stearic acid or montanic acid is preferable as the higher fatty acid.

(Metal salts of higher fatty acids)
The higher fatty acid metal salt is a metal salt of a higher fatty acid.
Examples of the metal element of the metal salt include a Group 1 element, a Group 2 element and a Group 3 element of the periodic table of the elements, zinc, and aluminum.
Examples of Group 1 elements of the periodic table include sodium, potassium, and the like.
Examples of the Group 2 element of the periodic table include calcium, magnesium, and the like.
Examples of Group 3 elements of the periodic table include scandium, yttrium, and the like.
Among them, an element of Groups 1 and 2 of the periodic table or aluminum is preferable, and sodium, potassium, calcium, magnesium, or aluminum is more preferable.

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

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

(Higher fatty acid amide)
The 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, ethylenebisstearylamide, ethylenebisoleylamide, N-stearylstearic acid amide, N-stearylerucic acid amide and the like.
Each of these higher fatty acids, metal salts of higher fatty acids, higher fatty acid esters and higher fatty acid amides may be used alone or in combination of two or more.

[(F) Heat stabilizer]
(F) Examples of the heat stabilizer include, but are not limited to, phenol-based heat stabilizers, phosphorus-based heat stabilizers, amine-based heat stabilizers, and groups 3 and 4 of the periodic table of the elements. Metal salts of elements of Groups 14 to 14, halides of alkali metals and alkaline earth metals, and the like.

(Phenolic heat stabilizer)
The phenolic heat stabilizer is not limited to the following, but includes, for example, a hindered phenol compound. 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, N, N'-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionate). Onamide), pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-t-butyl- 4-hydroxy-hydrocinnamamide), triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3 -T-butyl-4-hydroxy-5-methylphenyl) propynyloxy] -1,1-dimethylethyl {-2,4,8,10-tetraoxaspiro [5,5] undecane 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) Benzene and 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid and the like can be mentioned.
These may be used alone or as a combination of two or more hindered phenol compounds.
Particularly, from the viewpoint of improving heat aging resistance, hindered phenol compounds include N, N'-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide). )] Is preferred.

When a phenolic heat stabilizer is used, the content of the phenolic 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. The content is more preferably from 1% by mass to 1% by mass.
When the content of the phenolic heat stabilizer is in the above range, the heat-resistant aging property of the polyamide composition can be further improved, and the amount of gas generated can be further reduced.

(Phosphorus heat stabilizer)
Examples of the phosphorus-based heat stabilizer include, but are not limited to, pentaerythritol type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, tris isodecyl Phosphite, phenyldiisodecylphosphite, phenyldi (tridecyl) phosphite, diphenylisooctylphosphite, diphenylisodecylphosphite, diphenyl (tridecyl) phosphite, triphenylphosphite, tris (nonylphenyl) phosphite, tris (2 , 4-di-t-butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, 4,4'-butylidene- Bis (3-methyl-6-t-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4'-isopropylidenediphenyldiphosphite, 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) Butanediphosphite, tetra (tridecyl) -4,4'-butylidenebis (3-methyl-6-t-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4'-isopropylidenediphenyldiphosphite , Tris (mono- and di-mixed nonylphenyl) phosphite, 4,4'-isopropylidene Tris (3-tert-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'-isopropylidenediphenyl 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 4,4'-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′-biphenylenediphosphite and tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosph Fight and the like.
One of these phosphorus-based heat stabilizers may be used alone, or two or more thereof may be used in combination.
Above all, as the phosphorus-based heat stabilizer, a pentaerythritol-type phosphite compound 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 generated gas. ) One or more members 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 Phyte, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-octylphenyl-pentaerythritol diphosphite, 2,6-di-tert-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 diphosphite Phosphite and the like.
These pentaerythritol type phosphite compounds may be used alone or in combination of two or more.
Above all, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2 , 6-Di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,6 And at least one member selected from the group consisting of -di-t-octyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphos Fight is more preferred.

When a phosphorus-based heat stabilizer is used, the content of the phosphorus-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. The content is more preferably from 1% by mass to 1% by mass.
When the content of the phosphorus-based heat stabilizer is within the above range, the heat-resistant aging property 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 and 4-stearoyloxy-2,2,6,6-tetramer. 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-piperidyltolyl-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-hydroxyphene Le) propionyloxy] 2,2,6,6-tetramethylpiperidine, 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, and condensates with β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol.
One of these amine heat stabilizers may be used alone, or two or more thereof may be used in combination.

When an amine-based heat stabilizer is used, the content of the amine-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. The content is more preferably from 1% by mass to 1% by mass.
When the content of the amine-based heat stabilizer is within the above range, the heat-resistant aging property of the polyamide composition can be further improved, and the amount of generated gas can be further reduced.

(Metal salts of elements of Groups 3, 4 and 11 to 14 of the Periodic Table of the Elements)
The metal salts of the elements of Groups 3, 4 and 11 to 14 of the Periodic Table of the Elements are not particularly limited as long as they are salts of metals belonging to these groups.
Among them, a copper salt is preferable from the viewpoint of further improving the heat aging resistance of the polyamide composition. Examples of such copper salts include, but are not limited to, copper halide, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, and stearic acid. Copper and a copper complex salt in which copper is coordinated with a chelating agent.
Examples of the copper halide include copper iodide, cuprous bromide, cupric bromide, cuprous chloride and the like.
Examples of the chelating agent include ethylenediamine, ethylenediaminetetraacetic acid and the like.
These copper salts may be used alone or in a combination of two or more.
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 is composed of copper iodide and copper acetate. One or more selected from the group is more preferable. When the above-mentioned preferred copper salt is used, it is more excellent in heat aging resistance, and more effectively suppresses metal corrosion of the screw or cylinder portion during extrusion (hereinafter, sometimes simply referred to as “metal corrosion”). The resulting polyamide composition is obtained.

(F) When a copper salt is used as the 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). It is preferably from 0.01% by mass to 0.60% by mass, more preferably from 0.02% by mass to 0.40% by mass.
When the content of the copper salt is in the above range, the heat-resistant aging property of the polyamide composition can be further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

Also, concentration of the copper elements derived from the copper salts described above, from the viewpoint of improving the thermal aging resistance of the polyamide composition, the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) 10 ⁶ parts by weight The amount is preferably from 10 parts by mass to 2,000 parts by mass, more preferably from 30 parts by mass to 1500 parts by mass, even more preferably from 50 parts by mass to 500 parts by mass, based on (1 million parts by mass).

(Halides of alkali metals and alkaline earth metals)
Examples of the alkali metal and alkaline earth metal halides include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, and sodium chloride.
These alkali metal and alkaline earth metal halides may be used alone or in a combination of two or more.
Above all, as the halides of alkali metals and alkaline earth metals, one or more selected from the group consisting of potassium iodide and potassium bromide are preferable from the viewpoint of improving heat aging resistance and suppressing metal corrosion. Potassium is more preferred.

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

As the component of the heat stabilizer (F) described above, one type may be used alone, or two or more types may be used in combination.
Among them, as the (F) heat stabilizer, 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 of the copper salt to the halide of an alkali metal and an alkaline earth metal is preferably from 2/1 to 40/1 as a molar ratio of halogen to copper (halogen / copper), and more preferably from 5/1 to 30/30. 1 or less is more preferable.
When the molar ratio of halogen to copper (halogen / copper) is within the above range, the heat-resistant aging property of the polyamide composition can be further improved.
In addition, when the molar ratio of halogen to copper (halogen / copper) is equal to or more than the above lower limit, precipitation of copper and metal corrosion can be more effectively suppressed. On the other hand, when the molar ratio of halogen to copper (halogen / copper) is equal to or less than the above upper limit, corrosion of screws and the like of a molding machine can be more effectively prevented without substantially impairing mechanical properties (toughness or the like).

[(G) Other polymers]
(G) The other polymer is not particularly limited as long as it is other than polyamide. Examples thereof include polyester, liquid crystal polyester, polyphenylene sulfide, polyphenylene ether, polycarbonate, polyarylate, phenol resin, and epoxy resin. Is mentioned. Examples of the polyester include, but are not limited to, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate, and polyethylene naphthalate.

  (G) The content of the other polymer is preferably from 1 part by mass to 200 parts by mass, more preferably from 5 parts by mass to 100 parts by mass, and more preferably from 5 parts by mass to 50 parts by mass based on 100 parts by mass of the total amount of polyamide. Part by mass or less is more preferable. (G) When the content of the other polymer is within the above range, a polyamide composition having excellent heat resistance and releasability can be obtained.

[(H) at least one metal salt selected from the group consisting of metal phosphites and metal hypophosphites]
(H) The at least one metal salt selected from the group consisting of a metal phosphite and a metal hypophosphite includes, for example, phosphorous acid, hypophosphorous acid, pyrophosphorous acid or diphosphorous acid And salts with elements of the first and second groups of the periodic table, manganese, zinc, aluminum, ammonia, alkylamines, cycloalkylamines or diamines.
Especially, as a metal phosphite and a metal hypophosphite, sodium hypophosphite, calcium hypophosphite, or magnesium hypophosphite is preferred.
By containing at least one selected from the group consisting of these metal phosphites and metal hypophosphites, it is possible to obtain a polyamide composition having more excellent extrudability and molding stability.

[(J) Phosphite compound]
(J) Examples of the phosphite compound include triphenyl phosphite, tributyl phosphite and the like.
By adding the phosphite compound, a polyamide composition having more excellent 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, tris isodecyl phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phosphite Phyte, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl 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 -Di-t Butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 4,4'-butylidene-bis (3-methyl-6 -Tert-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-ditridecylphosphite-5-tert-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;
One of these phosphite compounds may be used alone, or two or more thereof may be used in combination.

[(K) Other additives]
The polyamide composition obtained by the production method of the present embodiment includes, in addition to the components (A) and (B), a range in which the effects of the polyamide composition obtained by the production method of the present embodiment are not impaired. The polyamide composition may contain (K) other additives commonly used in polyamide compositions. (K) Other additives include, for example, coloring agents such as pigments and dyes (including coloring masterbatches), flame retardants, fibrillating agents, fluorescent bleaching agents, plasticizers, antioxidants, ultraviolet absorbers, and electrification agents. Examples include an inhibitor, a flow improver, a spreading agent, and an elastomer.
When the polyamide composition obtained by the production method of the present embodiment contains (K) other additives, the content of (K) other additives varies depending on the type, use of the polyamide composition, and the like. There is no particular limitation as long as the effects of the polyamide composition obtained by the production method of the present embodiment are not impaired.

<Method for producing polyamide composition>
The method for producing the polyamide composition of the present embodiment is particularly limited as long as it includes a step of melt-kneading the raw material components including the (A) aliphatic polyamide and (B) the semi-aromatic polyamide. Not something. For example, the method includes a step of melting and kneading a raw material component containing the (A) aliphatic polyamide and the (B) semi-aromatic polyamide with an extruder. C. or lower is preferred.

  As a method of melt-kneading raw material components including polyamide, for example, the above-mentioned (A) aliphatic polyamide and (B) semi-aromatic polyamide and other raw materials are mixed using a tumbler, a Henschel mixer, and the like, and then melt-kneaded. Or a method of mixing other raw materials from the side feeder with the (A) aliphatic polyamide and (B) semi-aromatic polyamide melted by a single or twin screw extruder. Is mentioned.

  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 one time, or the components may be supplied from different supply ports.

The melt-kneading temperature is preferably about 250 ° C. or more and 350 ° C. or less in terms of resin temperature.
The melt-kneading time is preferably from about 0.25 minutes to about 5 minutes.
The apparatus for performing the melt kneading is not particularly limited, and for example, a known melt kneader such as a single-screw or twin-screw extruder, a Banbury mixer, and a mixing roll can be used.

≪Molded product≫
The molded article of the present embodiment is obtained by molding the above polyamide composition.
Further, the molded article of the present embodiment has a high surface gloss value. The surface gloss value of the molded article of the present embodiment is preferably 50 or more, more preferably 55 or more, and still more preferably 60 or more. When the surface gloss value of the molded product is equal to or more than the above lower limit, the obtained molded product is used as various parts such as for automobiles, electric and electronic, industrial materials, industrial materials, and for daily and household products. It can be suitably used.

The method for producing the molded article is not particularly limited, and a known molding method can be used.
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, melt spinning. And other generally known plastic molding methods.

  Since a molded article obtained by molding the polyamide composition obtained by the production method of the present embodiment is obtained from the polyamide composition, mechanical properties, particularly, water absorption rigidity, thermal rigidity, fluidity, surface properties, and corrosion resistance are obtained. Excellent in nature. Therefore, this molded article is used as various parts such as automobile parts, electric and electronic parts, home electric parts, OA (Office Automation) equipment parts, portable equipment parts, industrial equipment parts, daily necessities and household goods, and extrusion applications. Can be suitably used. Among them, molded articles are suitably used as automobile parts, electric and electronic parts, home electric appliance parts, OA equipment parts, or portable equipment parts.

  The automotive parts are not particularly limited, but include, for example, intake system parts, cooling system parts, fuel system parts, interior parts, exterior parts, and electrical parts.

Although there are no particular limitations on the vehicle intake system components, for example, 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, a throttle body and the like can be mentioned.
Examples of the automotive cooling system component include, but are not particularly limited to, a chain cover, a thermostat housing, an outlet pipe, a radiator tank, an alternator, and a delivery pipe.
Although there is no particular limitation on automotive fuel system components, examples thereof include a fuel delivery pipe and a gasoline tank case.
The automotive interior parts are not particularly limited, but include, for example, instrument panels, console boxes, glove boxes, steering wheels, trims, and the like.
Although there is no particular limitation on the exterior parts of the automobile, for example, a molding, a lamp housing, a front grill, a mudguard, a side bumper, a door mirror stay, a roof rail and the like can be mentioned.
Although there are no particular limitations on the automotive electrical components, examples thereof include a connector, a wire harness connector, a motor component, a lamp socket, a sensor-mounted switch, and a combination switch.

The electrical and electronic components are not particularly limited, and include, for example, connectors, light emitting device reflectors, switches, relays, printed wiring boards, electronic component housings, outlets, noise filters, coil bobbins, motor end caps, and the like.
As a reflector for a light emitting device, in addition to a light emitting diode (LED), a semiconductor package such as an optical semiconductor such as a laser diode (LD), a photo diode, a charge-coupled device (CCD), and a complementary metal oxide semiconductor (CMOS). Can be widely used.

  The mobile device components are not particularly limited, but examples include a housing and a structure of a mobile phone, a smartphone, a personal computer, a mobile game device, a digital camera, and the like.

  Industrial equipment parts are not particularly limited, and include, for example, gears, cams, insulating blocks, valves, power tool parts, agricultural equipment parts, engine covers, and the like.

  The daily necessities and household goods are not particularly limited, but include, for example, buttons, food containers, office furniture, and the like.

  The application for extrusion is not particularly limited, but for example, it is used for films, sheets, filaments, tubes, rods, hollow molded articles and the like.

The molded article of the present embodiment is particularly suitable for a structural material for exterior use among these various uses.
The exterior structural material is a mechanical component or a structural component that requires surface workability of a molded product (for example, graining processability, high surface glossiness, and the like) and requires relatively high strength and rigidity. Specific examples of the exterior structural material include furniture articles, OA equipment field articles, automobile parts, electric field articles, and other field articles. Furniture articles include, for example, desk legs, chair legs, seats, cabins, wagon parts, and the like. Examples of the OA equipment field supplies include a notebook personal computer housing and the like. Examples of the automotive parts include a door mirror stay, a wheel rim, a wheel spoke, a wheel cap, a wiper, a motor fan, a seat lock part, a gear, a lamp housing, a saddle, a saddle post, a handle, a stand, a carrier, and the like. Examples of the electric field products include pulleys, gears, hot air blower housings, and the like. Other field products include, for example, valve housings, nails, screws, bolts, bolt nuts, and the like.

Further, the molded article of the present embodiment is excellent in surface appearance, and thus is preferably used as a molded article having a coating film formed on the surface of the molded article. The method for forming the coating film is not particularly limited as long as it is a known method. For example, a coating method such as a spray method or an electrostatic coating method can be used. The paint used for the coating is not particularly limited as long as it is a known one, and a melamine crosslinked polyester polyol resin paint, an acrylic urethane-based paint, or the like can be used.
Among them, the molded article of the present embodiment is excellent in mechanical strength, toughness, heat resistance and vibration fatigue resistance, so that it is suitable as a component material for automobiles, and further, because it has excellent slidability. It is particularly suitable as a component material for gears and bearings. Further, since it has excellent mechanical strength, toughness, and heat resistance, it is suitable as a component material for electric and electronic devices.

Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples. In this example, 1 kg / cm ² means 0.098 MPa.

  First, (A) an aliphatic polyamide, (B) a semi-aromatic polyamide, and (C) an inorganic filler used in Examples and Comparative Examples are shown below.

<Components>
[(A) Aliphatic polyamide]
A-1: Polyamide 66 (Mw (A) = 35000, Mw (A) / Mn (A) = 2.0)
A-2: Polyamide 66 (Mw (A) = 30000, Mw (A) / Mn (A) = 2.0, sealed terminal amount: 20 μeq / g)

[(B) Semi-aromatic polyamide]
B-1: Polyamide 6I (Mw (B) = 20,000, Mw (B) / Mn (B) = 2.0, sealed terminal amount: 150 μeq / g, total of amino terminal amount and carboxyl group terminal amount : 110 μeq / g)
B-2: Polyamide 6I (Mw (B) = 20,000, Mw (B) / Mn (B) = 2.0, total of amino terminal amount and carboxyl group terminal amount: 253 μeq / g)
B-3: Polyamide 6IT-40 (manufactured by LANXESS, Mw (B) = 44000, Mw (B) / Mn (B) = 2.8, total of amino terminal amount and carboxyl group terminal amount: 147 μeq / g) )

[(C) inorganic filler]
C-1: Glass fiber (GF) (manufactured by Nippon Electric Glass, trade name "ECS03T275H", number average fiber diameter (average particle diameter): 10 μm (true circle), cut length: 3 mm)
In addition, in this example, the average fiber diameter of the glass fiber was measured as follows.
First, the polyamide composition was placed in an electric furnace, and organic substances contained in the polyamide composition were incinerated. From the residue after the treatment, 100 or more glass fibers arbitrarily selected were observed with a scanning electron microscope (SEM), and the number average fiber diameter was determined by measuring the fiber diameter of these glass fibers. .

<Raw material of polyamide>
(A) Aliphatic polyamide and (B) semi-aromatic polyamide used in the present Examples and Comparative Examples were produced by appropriately using the following (a) and (b).

[(A) dicarboxylic acid)]
(A-1) Adipic acid (ADA) (manufactured by Wako Pure Chemical Industries)
(A-2) Isophthalic acid (IPA) (manufactured by Wako Pure Chemical Industries)

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

<Manufacture of polyamide>
Next, a method for producing (A) aliphatic polyamides A-1 and A-2 and (B) semi-aromatic polyamides B-1 and B-2 will be described.

[Production Example 1] Production of aliphatic polyamide A-1 (polyamide 66) A polyamide polymerization reaction was carried out as follows by a "hot melt polymerization method".
An equimolar salt of adipic acid and hexamethylenediamine: 1500 g was dissolved in distilled water: 1500 g to prepare an equimolar 50% by mass homogeneous aqueous solution of the raw material monomer. This aqueous solution was charged into an autoclave having an internal volume of 5.4 L, and was replaced with nitrogen. While stirring at a temperature of 110 ° C. or more and 150 ° C. or less, water vapor was gradually removed to a solution concentration of 70% by mass and concentrated. Thereafter, the internal temperature was raised to 220 ° C. At this time, the pressure in the autoclave was increased to 1.8 MPa. The reaction was allowed to proceed for 1 hour while maintaining the pressure at 1.8 MPa by gradually removing steam until the internal temperature reached 245 ° C. for 1 hour. Next, the pressure was reduced over 1 hour. Thereafter, the inside of the autoclave was maintained at a reduced pressure of 650 torr for 10 minutes by a vacuum device. At this time, the final internal temperature of the polymerization was 265 ° C. Thereafter, the mixture is pressurized with nitrogen to form a strand from the lower spinneret (nozzle), water-cooled, cut, discharged in the form of a pellet, dried at 100 ° C. under a nitrogen atmosphere for 12 hours, and dried with an aliphatic polyamide A-1 (polyamide 66). ) Got. Mw (A) = 35000 and Mw (A) / Mn (A) = 2.0.

[Production Example 2] Production of aliphatic polyamide A-2 (polyamide 66) Equimolar salt of adipic acid and hexamethylenediamine: 1500 g, and acetic acid of 0.5 mol% with respect to all equimolar salt components was distilled. Water: A polymerization reaction of polyamide was carried out using the same method as that described in Production Example 1 except that it was dissolved in 1500 g to prepare a uniform aqueous solution of 50% by mass of an equimolar amount of the raw material monomer (“hot melt weight”). Legally "), to obtain pellets of aliphatic polyamide A-2 (polyamide 66). Mw (A) = 30000, Mw (A) / Mn (A) = 2.0, and the amount of capped ends: 20 μeq / g.

[Production Example 3] Semi-aromatic polyamide B-1 (polyamide 6I)
The polymerization reaction of the polyamide was carried out by the “hot melt polymerization method” as follows.
Equimolar salt of isophthalic acid and hexamethylenediamine: 1500 g, and 4.0 mol% of acetic acid with respect to all equimolar salt components dissolved in distilled water: 1500 g, and an equimolar 50% by mass homogeneous aqueous solution of the raw material monomer Was prepared. While stirring at a temperature of 110 ° C. or more and 150 ° C. or less, water vapor was gradually removed to a solution concentration of 70% by mass and concentrated. Thereafter, the internal temperature was raised to 220 ° C. At this time, the pressure in the autoclave was increased to 1.8 MPa. The reaction was allowed to proceed for 1 hour while maintaining the pressure at 1.8 MPa by gradually removing steam until the internal temperature reached 245 ° C. for 1 hour. Next, the pressure was reduced over 30 minutes. Thereafter, the inside of the autoclave was maintained at a reduced pressure of 650 torr for 10 minutes by a vacuum device. At this time, the final internal temperature of the polymerization was 265 ° C. Thereafter, the mixture is pressurized with nitrogen to form a strand from a lower spinneret (nozzle), water-cooled, cut, discharged in the form of a pellet, dried at 100 ° C. under a nitrogen atmosphere for 12 hours, and then subjected to semi-aromatic polyamide B-1 (polyamide). 6I) was obtained. Mw (B) = 20,000, Mw (B) / Mn (B) = 2.0, sealed terminal amount: 150 μeq / g, total amount of amino terminal and carboxyl group terminal: 110 μeq / g. Was.

[Production Example 4] Semi-aromatic polyamide B-2 (polyamide 6I)
Equimolar salt of isophthalic acid and hexamethylenediamine: 1500 g, and 1.5 mol% excess adipic acid with respect to all equimolar salt components dissolved in distilled water: 1500 g, and equimolar 50 mass% of raw material monomer A polyamide polymerization reaction was performed by the method described in Production Example 3 (“hot melt polymerization method”), except that a homogeneous aqueous solution was prepared, to obtain pellets of semi-aromatic polyamide B-2 (polyamide 6I). Mw (B) = 20,000, Mw (B) / Mn (B) = 2.0, the total amount of amino terminal and carboxyl group terminal: 253 μeq / g.

<Production of polyamide composition>
[Examples 1 to 3 and Comparative Examples 1 and 2]
Using the (A) aliphatic polyamide and (B) semi-aromatic polyamide in the types and ratios shown in Table 1 below, polyamide compositions were produced as follows.
Each of the polyamides obtained in the above Production Examples was dried in a nitrogen stream to adjust the water content to about 0.2% by mass, and then used as a raw material of the polyamide composition.

A twin-screw extruder [ZSK-26MC: manufactured by Coperion (Germany)] was used as a polyamide composition manufacturing apparatus.
The twin screw extruder has an upstream supply port in the first barrel from the extruder upstream, 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 of each (A) polyamide produced in the above production example + 20 ° C., the screw rotation speed was set to 250 rpm, and the discharge rate was set to 25 kg / h.

  (A) Aliphatic polyamide and (B) semi-aromatic polyamide are dry-blended and then supplied from the upstream supply port of the twin-screw extruder and extruded from the die head so that the types and ratios are as shown in Table 1 below. The obtained melt-kneaded product was cooled in a strand shape and pelletized to obtain a polyamide composition pellet (containing no GF).

Next, the case of producing a polyamide composition containing 60% by mass of GF shown in Table 1 (polyamide: GF = 100 parts by mass: 150 parts by mass) will be described. (A) Aliphatic polyamide and (B) semi-aromatic polyamide are dry-blended and then supplied from an upstream supply port of a twin-screw extruder. Glass fiber was supplied as a filler, and the melt-kneaded product extruded from the die head was cooled in a strand shape and pelletized to obtain a polyamide composition pellet (including GF).
The obtained pellets of the polyamide composition were dried in a stream of nitrogen to reduce the water content in the polyamide composition to 500 ppm or less.

<Method for measuring properties of polyamide composition>
The following various physical properties were evaluated using the polyamide composition after adjusting the water content. The evaluation results are shown in Table 1 below.

[Physical properties 1] Melting peak temperature Tm2 (melting point), crystallization peak temperature Tc, crystallization enthalpy Measured using PERKIN-ELMER's Diamond-DSC according to JIS-K7121. Specifically, the measurement was performed as follows.
First, under a nitrogen atmosphere, about 10 mg of a sample was heated from room temperature to 300 ° C. or more and 350 ° C. or less at a heating rate of 20 ° C./min according to the melting point of the sample. The highest peak temperature of the endothermic peak (melting peak) appearing at this time was defined as Tm1 (° C.). Next, the temperature was kept at the highest temperature for 2 minutes. At this maximum temperature, the polyamide was in the molten state. Thereafter, the temperature was lowered to 30 ° C. at a temperature lowering rate of 20 ° C./min. The exothermic peak appearing at this time was defined as a crystallization peak, the crystallization peak temperature was defined as Tc, and the crystallization peak area was defined as crystallization enthalpy ΔH (J / g). Then, after holding at 30 ° C. for 2 minutes, the temperature was raised from 30 ° C. to 280 ° C. or more and 300 ° C. or less according to the melting point of the sample at a rate of 20 ° C./min. The highest peak temperature of the endothermic peak (melting peak) appearing at this time was defined as a melting point Tm2 (° C.).

[Physical properties 2] Tan δ peak temperature Using a viscoelasticity measurement analyzer (DVE-V4 manufactured by Rheology), a temperature dispersion spectrum of dynamic viscoelasticity of a test piece obtained by cutting a parallel portion of an ASTM D1822 TYPE L test piece into a strip shape. Was measured under the following conditions. The dimensions of the test piece were 3.1 mm (width) x 2.9 mm (thickness) x 15 mm (length: distance between grips).

(Measurement condition)
Measurement mode: tensile Waveform: sine wave Frequency: 3.5 Hz
Temperature range: 0 ° C or higher and 180 ° C or lower Temperature rising step: 2 ° C / min
Static load: 400g
Displacement amplitude: 0.75 μm

  The ratio (E2 / E1) of the loss modulus E2 to the storage modulus E1 was defined as tan δ, and the highest temperature was defined as the tan δ peak temperature.

[Physical properties 3] Mw (weight average molecular weight), Mn (number average molecular weight), molecular weight distribution Mw / Mn, Mw (A) -Mw (B)
Mw (weight average molecular weight) and Mn (number average molecular weight) were measured using GPC (manufactured by Tosoh Corporation, HLC-8020, hexafluoroisopropanol solvent, PMMA (polymethyl methacrylate) standard sample (manufactured by Polymer Laboratories)). It was measured. From the values, Mw (A) -Mn (B) and molecular weight distribution Mw / Mn were calculated.
The content (% by mass) in which the number average molecular weight Mn is 500 or more and 2000 or less is determined from an elution curve (vertical axis: signal intensity obtained from a detector, horizontal axis: elution time) of each sample obtained using GPC. It was calculated from the area of the region surrounded by the base line and the elution curve and having a number average molecular weight of 500 or more and less than 2000, and the area of the region surrounded by the baseline and the elution curve.

[Physical property 4] [NH ₂ ] / ([NH ₂ ] + [COOH])
[NH ₂ ] / ([NH ₂ ] + [[NH ₂ ] + [NH ₂ ]), depending on the amount of amino terminal ([NH ₂ ]) measured by the following (4-1) and (4-2) and the amount of carboxyl terminal ([COOH]). [COOH]).

(4-1) Amount of amino terminal ([NH ₂ ])
The amount of amino terminal bound to the polymer terminal of the polyamide composition was measured by neutralization titration as follows.
3.0 g of the polyamide composition was dissolved in 100 mL of a 90% by mass aqueous phenol solution, and the obtained solution was titrated with 0.025 N hydrochloric acid to determine the amino terminal amount (μ equivalent / g). The end point was determined from the pH meter reading.

(4-2) Carboxyl terminal amount ([COOH])
The amount of carboxyl terminal bound to the polymer terminal of the polyamide composition was measured by neutralization titration as follows.
4.0 g of the polyamide composition was dissolved in 50 mL of benzyl alcohol, and the obtained solution was titrated with 0.1 N NaOH to determine the amount of carboxyl terminal (μ equivalent / g). The end point was determined from the discoloration of the phenolphthalein indicator.

[Physical Properties 5] Blocked Terminal Amount The content of the blocked terminal of the polyamide contained in the polyamide composition, aliphatic polyamide and semi-aromatic polyamide was quantified by ¹ H-NMR measurement as follows.
15 mg of the polyamide composition, aliphatic polyamide and semi-aromatic polyamide were dissolved in a mixed solvent of sulfuric acid deuteride: 0.7 g and trifluoroacetic acid deuteride: 0.7 g, and the mixture was allowed to stand overnight. Thereafter, using the obtained solution, ¹ H-NMR analysis was performed using a nuclear magnetic resonance analyzer JNM ECA-500 manufactured by JEOL Ltd., and the terminal was measured.
Calculating the integration ratio from the peak area of 1.98 ppm derived from the proton of acetic acid bonded to the terminal of the aliphatic diamine unit, based on the peak area of 3.04 ppm derived from the methylene group proton of the main chain amine. Was used to determine the amount of capped ends.

[Physical property 6] [NH ₂ ] + [COOH]
The carboxyl terminal and amino terminal contents of the polyamide contained in the polyamide composition and the semi-aromatic polyamide were quantified by ¹ H-NMR measurement as follows.
The polyamide composition and the semi-aromatic polyamide: 15 mg were dissolved in a mixed solvent of sulfuric acid deuteride: 0.7 g and trifluoroacetic acid deuteride: 0.7 g, and the mixture was allowed to stand overnight. Thereafter, using the obtained solution, ¹ H-NMR analysis was performed using a nuclear magnetic resonance analyzer JNM ECA-500 manufactured by JEOL Ltd., and the terminal was measured.
Based on the peak area of 3.04 ppm derived from the proton of the methylene group of the main chain amine, the peak area of 2.47 ppm derived from the adjacent methylene hydrogen of adipic acid and the hydrogen derived from the hydrogen on the adjacent benzene ring carbon of the isophthalic acid unit. From the 8.07 ppm peak area and 7.85 ppm peak area derived from hydrogen on the adjacent benzene ring carbon in the terephthalic acid unit, the carboxyl terminal amount was determined by calculating the integration ratio. The amount of amino terminal was determined by calculating the integration ratio from the peak area of 2.67 to 2.69 ppm derived from hydrogen on the adjacent methylene carbon of the hexamethylenediamine group.
[NH ₂ ] + [COOH] was calculated from the amino terminal amount ([NH ₂ ]) and the carboxyl terminal amount ([COOH]) measured as described above.

[Physical properties 7] Tensile strength Each of the test pieces was molded into a multipurpose test piece A-type according to ISO3167 using an injection molding machine [PS-40E: manufactured by Nissei Plastic Co., Ltd.]. Specific molding conditions were as follows: injection + holding time: 25 seconds; cooling time: 15 seconds; mold temperature: 80 ° C .; molten resin temperature: polyamide high-temperature side melting peak temperature (Tm2) + 20 ° C.
Using the obtained multipurpose test piece A-type molded piece, a tensile test was conducted at a tensile speed of 50 mm / min under a temperature condition of 23 ° C. in accordance with ISO 527, and a tensile yield stress was measured to obtain a tensile strength.
Further, the temperature condition was set to 80 ° C., and the other conditions were the same as above, and the tensile strength at 80 ° C. was measured.

[Physical property 8] Corrosion resistance A sample pellet and carbon steel (SS400) whose weight was measured were placed in a SUS closed container, and nitrogen replacement was performed. Thereafter, the sealed container was heated and maintained at an internal temperature of 300 ° C. for 10 hours, and after cooling, the weight of the carbon steel was measured. The degree of corrosion was determined by the weight change of the carbon steel, and the corrosion resistance was evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: No weight loss before and after the test B: Weight change before and after the test is 0.1 g or more and less than 0.5 g C: Weight change before and after the test is 0.5 g or more and less than 1 g D: Weight change before and after the test 1g or more

[Physical properties 9] Surface gloss value A flat plate molded piece was produced as follows.
Using an injection molding machine [NEX50III-5EG: manufactured by Nissei Plastic Industry Co., Ltd.], cooling time is 25 seconds, screw rotation speed is 200 rpm, mold temperature is Tan δ peak temperature + 5 ° C., cylinder temperature = (Tm2 + 10) ° C. or more (Tm2 + 30) ° C or lower, and the injection pressure and injection speed were appropriately adjusted so that the filling time was in the range of 2.0 ± 0.1 seconds to produce a flat plate molded piece (6 cm × 9 cm, thickness 2 mm). .
The 60-degree gloss of the central part of the flat plate molded piece thus produced was measured using a gloss meter (IG320 manufactured by HORIBA) according to JIS-K7150. The larger the measured value, the better the surface appearance.

[Physical Properties 10] MD (Mold Deposit) at the time of molding
The molding described in “Physical Properties 9” was performed continuously for 500 shots, and the gas vent after the completion of 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 any problem would lead to an improvement in productivity.

(Evaluation criteria)
A: No deposit is found on the gas vent B: There is a deposit on the gas vent C: There is a deposit on the gas vent and it is almost clogged D: There is an deposit on the gas vent and there is clogging

[Physical properties 11] Flexural modulus retention after water absorption An ISO dumbbell having a thickness of 4 mm was prepared and used as a test piece. Using the obtained test piece, the flexural modulus was measured in accordance with ISO178. Further, the ISO dumbbell was allowed to stand in a constant temperature and humidity (23 ° C., 50 RH%) atmosphere to reach a water absorption equilibrium, and then the flexural modulus was measured according to ISO178. The flexural modulus retention after water absorption was determined using the following equation.

  Flexural modulus retention after water absorption (%) = Flexural modulus after water absorption / Flexural modulus before water absorption x 100

As shown in Table 1, (A) the aliphatic polyamide contains 50 parts by mass or more and 99 parts by mass or less, and (B) the semi-aromatic polyamide contains 1 part by mass or more and 50 parts by mass or less. And (B) at least one kind of polyamide selected from the group consisting of semi-aromatic polyamides, wherein the amount of the capped terminal expressed as an equivalent to 1 g of the polyamide is from 5 μeq / g to 180 μeq / g, and Molded articles using the polyamide composition having a Tan δ peak temperature of 90 ° C. or higher (Examples 1 to 3) have a polyamide composition in which the amount of capped terminals is 0 (that is, the terminals are not capped). Was excellent in the MD at the time of molding, the surface gloss value, and the corrosion resistance, as compared with the molded products using Comparative Examples 1 and 2 (Comparative Examples 1 and 2).
In addition, molded articles (Examples 1 and 2) using a polyamide composition having a sealed terminal amount of 40 µ equivalent g or more use a polyamide composition having a sealed terminal amount of less than 40 µ equivalent g. The MD and the corrosion resistance at the time of molding were particularly better than those of the molded article (Example 3).

  The polyamide composition according to the present invention has excellent mechanical properties, in particular, water absorption rigidity, rigidity at heat, fluidity, surface appearance, corrosion resistance, etc., for automobiles, electric and electronic, industrial materials, industrial materials, and It can be suitably used as a molding material for various parts such as for daily use and household use.

Claims (21)

50 parts by mass or more and 99 parts by mass or less of (A) an aliphatic polyamide comprising a diamine and a dicarboxylic acid, and
1 part by mass or more and 50 parts by mass of (B) a semi-aromatic polyamide containing a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and at least 50 mol% of a diamine unit having 4 to 10 carbon atoms. Less than,
A polyamide composition containing
The amount of the capped terminal expressed as an equivalent to 1 g of at least one kind of polyamide selected from the group consisting of the (A) aliphatic polyamide and the (B) semi-aromatic polyamide is 5 μeq / g or more and 180 μeq / g. Is the following,
A polyamide composition, wherein the tan δ peak temperature of the polyamide composition is 90 ° C or higher.   The polyamide composition according to claim 1, wherein the amount of the terminal capped with acetic acid, expressed as an equivalent to 1 g of the (B) semi-aromatic polyamide, is 5 μe / g or more and 180 μe / g or less.   The polyamide composition according to claim 1, wherein the weight average molecular weight Mw of the polyamide composition is 15,000 or more and 35,000 or less.   The polyamide composition according to any one of claims 1 to 3, wherein a molecular weight distribution Mw / Mn of the polyamide composition is 2.6 or less.   The total amount of the amino terminal and the carboxyl terminal expressed as equivalents to 1 g of the polyamide in the polyamide composition is 70 μe / g or more and 145 μe / g or less, according to any one of claims 1 to 4. Polyamide composition.   The ratio of the amount of amino terminal to the total amount of the amount of amino terminal and carboxyl terminal (the amount of amino terminal / (the amount of amino terminal + the amount of carboxyl terminal)) is 0.25 or more and less than 0.4. A polyamide composition according to claim 1.   The polyamide composition according to any one of claims 1 to 6, wherein the (A) aliphatic polyamide is polyamide 66 or polyamide 610.   The polyamide composition according to any one of claims 1 to 7, wherein in the (B) semi-aromatic polyamide, the content of the isophthalic acid unit relative to the total amount of the dicarboxylic acid units is 100 mol%.   The polyamide composition according to any one of claims 1 to 8, wherein the (B) semi-aromatic polyamide is polyamide 6I.   The polyamide composition according to any one of claims 1 to 9, wherein the semi-aromatic polyamide (B) has a weight average molecular weight Mw (B) of 10,000 or more and 25,000 or less.   The polyamide composition according to any one of claims 1 to 10, 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 aliphatic polyamide (A) and the weight average molecular weight Mw (B) of the semiaromatic polyamide (B) is 10,000 or more. The polyamide composition according to any one of claims 1 to 11.   The polyamide composition according to any one of claims 1 to 12, further comprising at least one metal salt selected from the group consisting of metal phosphites and metal hypophosphites.   The polyamide composition according to any one of claims 1 to 13, further comprising a phosphite compound.   The inorganic filler (C) is further contained in an amount of 5 to 250 parts by mass based on a total of 100 parts by mass of the (A) aliphatic polyamide and the (B) semi-aromatic polyamide. The polyamide composition according to claim 1.   A molded article obtained by molding the polyamide composition according to any one of claims 1 to 15 and having a surface gloss value of 50 or more. A semi-aromatic polyamide containing a dicarboxylic acid unit containing at least 75 mol% of an isophthalic acid unit and a diamine unit composed of a linear aliphatic diamine having 4 to 10 carbon atoms,
The amount of the capped terminal expressed as an equivalent to 1 g of the semi-aromatic polyamide is 5 μequivalent / g or more and 180 μequivalent / g or less;
The semi-aromatic polyamide, wherein the tan δ peak temperature of the semi-aromatic polyamide is 90 ° C. or higher.   The semi-aromatic polyamide according to claim 17, wherein the terminal amount capped with acetic acid, expressed as an equivalent to 1 g of the semi-aromatic polyamide, is 5 µeq / g or more and 180 µeq / g or less.   The semi-aromatic polyamide according to claim 17 or 18, wherein the total of the amount of amino terminal and the amount of carboxyl terminal expressed as equivalents to 1 g of the semi-aromatic polyamide is 50 µe / g or more and 155 µe / g or less.   The semi-aromatic polyamide according to any one of claims 17 to 19, wherein the semi-aromatic polyamide has a weight average molecular weight Mw of 10,000 or more and 35,000 or less.   The semi-aromatic polyamide according to any one of claims 17 to 20, wherein the molecular weight distribution Mw / Mn of the semi-aromatic polyamide is 2.6 or less.