JP2023113400A - POLYAMIDE RESIN, POLYAMIDE RESIN COMPOSITION, AND MOLDED PRODUCT - Google Patents

Abstract

A polyamide-based resin, a polyamide-based resin composition, and a molded product having improved moldability and durability while maintaining heat resistance are provided.
A polyamide-based resin comprising a polymer block (A) containing 50 mol% or more of constitutional units derived from a polyamide and a chain extender (B),
The content of the polymer block (A) in the polyamide resin is 91.0% by mass or more and less than 99.0% by mass,
A polyamide-based resin having a weight average molecular weight of 40,000 to 150,000.
[Selection figure] None

Description

TECHNICAL FIELD The present invention relates to polyamide resins, polyamide resin compositions, and molded articles.

In order to reduce the fuel consumption of internal combustion engine-powered vehicles and extend the cruising range of electric vehicles, there is a demand for lighter vehicles, and replacing metal parts with resin parts is an effective countermeasure. Various polyamides, which are excellent in heat resistance, durability, and chemical resistance, have been proposed as substitutes for metals, but the current situation is that they are not suitable for applications that require a high degree of durability.
Conventionally, it is known that increasing the molecular weight of a resin is effective in increasing durability such as fatigue resistance, creep resistance, and wear resistance (see, for example, Non-Patent Documents 1 to 3). However, the use of a high-molecular-weight resin is accompanied by an increase in the melt viscosity of the resin, so there is an upper limit to the molecular weight in order to ensure moldability. Therefore, when replacing metal parts with resin parts, there is a problem that durability is insufficient when trying to ensure moldability.
As a method for increasing the molecular weight of polyamide, it is known that the increase in resin melt viscosity can be suppressed by using a chain extender (see Patent Documents 1 to 4).

Japanese translation of PCT publication No. 2003-520877 Japanese Patent Application Publication No. 2017-511420 Japanese Patent Publication No. 2001-521576 JP-A-06-211986

Polymer life prediction and life extension technology, October 1, 2002, Publisher: NTS Co., Ltd., Zenjiro Osawa et al., pp. 166-183 Journal of Materials Science, 23(10), 3648-3655, 1988 TOSOH Research & Technology Review, Vol. 44, 64, 2000

However, in the production method of Patent Document 1, in which a chain extender is mixed in the polymerization stage of polyamide, there is a problem that the original physical properties of polyamide cannot be obtained.
In addition, properties other than the melt viscosity of the high-molecular-weight polyamide obtained by the method of blending a polyamide precursor with a chain extender and melt-kneading it in Patent Document 2 are unknown.
Moreover, the method of melt-polymerizing a relatively low-molecular-weight polyamide and a bislactam in Patent Document 3 does not specify the molecular weight of the resulting high-molecular-weight product.
Further, in Patent Document 4, a method of carrying out an addition reaction between an oligomer having a dicarboxyl end and a bisoxazoline discloses a relatively low-molecular-weight oligomer, but does not describe a high-molecular weight product.
Furthermore, Non-Patent Documents 1 to 3 describe the relationship between the molecular weight of the resin and the durability, but these only describe a simple resin structure, and the resin obtained by the chain extender is specifically described. No disclosures or suggestions.

Accordingly, there is a demand for a polyamide-based resin that has excellent moldability and durability such as fatigue resistance in addition to the excellent heat resistance of polyamide.
Accordingly, an object of the present invention is to provide a polyamide-based resin, a polyamide-based resin composition, and a molded article that have improved moldability and durability while maintaining heat resistance.

As a result of intensive studies in order to solve the above problems, the inventors have conceived the following invention and found that the problems can be solved.
That is, the present invention is as follows.
A polyamide-based resin comprising a polymer block (A) containing 50 mol% or more of structural units derived from a polyamide and a chain extender (B),
The content of the polymer block (A) in the polyamide resin is 91.0% by mass or more and less than 99.0% by mass,
A polyamide-based resin having a weight average molecular weight of 40,000 to 150,000.

ADVANTAGE OF THE INVENTION According to this invention, the polyamide-type resin which improved moldability and durability (fatigue resistance), a polyamide-type resin composition, and a molded article can be provided, maintaining heat resistance.

An example of the embodiment of the present invention will be described below. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following description.
Also, preferred forms of embodiments are indicated herein, and combinations of two or more of the individual preferred forms are also preferred forms. When there are several numerical ranges for items indicated by numerical ranges, the lower and upper limits thereof can be selectively combined to form a preferred form.
In this specification, when a numerical range is described as "XX to YY", it means "XX or more and YY or less".

[Polyamide resin]
The polyamide-based resin of the present embodiment is a polyamide-based resin containing a polymer block (A) containing 50 mol% or more of structural units derived from a polyamide and a chain extender (B), wherein the polyamide-based resin The content of the polymer block (A) in the polymer block (A) is 91.0% by mass or more and less than 99.0% by mass, and the weight average molecular weight of the polyamide resin is 40,000 to 150,000. .

The polyamide-based resin of this embodiment is a polymer containing polyamide as a polymer block (A) and obtained by reaction with a chain extender (B).
By having a specific weight average molecular weight, the polyamide-based resin of the present embodiment has good moldability (moldability) and excellent durability (fatigue resistance) while maintaining the excellent heat resistance of polyamide. can be demonstrated.

<Polymer block (A)>
The polymer block (A) contains 50 mol % or more of constitutional units derived from polyamide. From the viewpoint of easily obtaining even better heat resistance, the polymer block (A) preferably contains 70 mol% or more, more preferably 90 mol% or more, and more preferably 100 mol% of structural units derived from polyamide. You can also In the polymer block (A), structural units other than the polyamide-derived structural units are not limited as long as the effects of the present invention can be obtained.
Polyamides that can be used in the present embodiment are not limited as long as the effects of the present invention can be obtained, and examples thereof include semi-aromatic polyamides, wholly aromatic polyamides, and aliphatic polyamides.
Among them, semi-aromatic polyamides and aliphatic polyamides are exemplified as polyamides with which the effects of the present invention are exhibited more remarkably. It is particularly preferable to use a semi-aromatic polyamide as the polyamide from the viewpoint that even more excellent heat resistance can be easily obtained.
Examples of the aliphatic polyamide include polytetramethylene adipamide (polyamide 46) and polyhexamethylene adipamide (polyamide 66).
The semi-aromatic polyamide that can be preferably used in this embodiment will be described in detail below.

<<Semi-aromatic Polyamide>>
A semi-aromatic polyamide is a polyamide containing a diamine unit mainly composed of an aliphatic diamine unit and a dicarboxylic acid unit mainly composed of an aromatic dicarboxylic acid unit, or a polyamide mainly composed of an aliphatic dicarboxylic acid unit. A polyamide resin containing dicarboxylic acid units and diamine units mainly composed of aromatic diamine units. Here, "mainly composed" means to constitute 50 to 100 mol %, preferably 60 to 100 mol %, of all units.
In the present embodiment, the semi-aromatic polyamide may contain a diamine unit mainly composed of an aliphatic diamine unit and a dicarboxylic acid unit mainly composed of an aromatic dicarboxylic acid unit, from the viewpoint of better heat resistance. preferable.

(aliphatic diamine unit)
The semi-aromatic polyamide has 4 to 18 carbon atoms with respect to all diamine units from the viewpoint that the polymerization reaction with dicarboxylic acid proceeds well and is advantageous for improving physical properties such as heat resistance and durability (fatigue resistance). It preferably contains 30 mol% or more diamine units derived from an aliphatic diamine, more preferably 30 to 100 mol%, still more preferably 50 to 100 mol%, even more preferably 70 to 100 mol%, 90 to 100 mol% is more preferable, and 100 mol% may be contained.
The aliphatic diamine used in the diamine unit is more preferably an aliphatic diamine having 4 to 16 carbon atoms, more preferably an aliphatic diamine having 4 to 12 carbon atoms, and more preferably an aliphatic diamine having 6 to 12 carbon atoms. Aliphatic diamines having 6 to 10 carbon atoms are preferred, and more preferred.

Aliphatic diamines having 4 to 18 carbon atoms include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9 -nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15-pentadecanediamine, 1,16- Linear aliphatic diamines such as hexadecanediamine, 1,17-heptadecanediamine, 1,18-octadecanediamine;
1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, 1-ethyl-1,4-butanediamine, 2-ethyl-1,4-butanediamine, 1,2- Dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2-methyl-1,3-propanediamine, 2-methyl- 1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2-ethyl-1,5- pentanediamine, 2-propyl-1,5-pentanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1, 6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4, 4-trimethyl-1,6-hexanediamine, 2-ethyl-1,6-hexanediamine, 2-propyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2-ethyl- 1,7-heptanediamine, 2-propyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 1,3-dimethyl-1,8- octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1, 8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, 2-ethyl-1, Branched aliphatic diamines such as 8-octanediamine, 2-methyl-1,9-nonanediamine, 5-methyl-1,9-nonanediamine;
1,2-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5 - Alicyclic compounds such as trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, and bis(aminopropyl)piperazine diamine; and the like. These may be used individually by 1 type, and may use 2 or more types together.
From the viewpoint of heat resistance, the aliphatic diamine is preferably at least one selected from the group consisting of linear aliphatic diamines and branched aliphatic diamines, and linear aliphatic diamines and branched aliphatic diamines. It is more preferable to use a diamine together.

Semi-aromatic polyamides are 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, and 2-propyl, from the viewpoint that the effects of the present invention are exhibited more remarkably and raw material availability is also excellent. -1,6-hexanediamine, 2-ethyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecane It preferably contains a diamine unit derived from at least one selected from the group consisting of diamines, and a diamine derived from at least one selected from the group consisting of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. It is more preferable to contain units, and from the viewpoint of moldability, it is even more preferable to use both 1,9-nonanediamine and 2-methyl-1,8-octanediamine in combination. The content of 1,9-nonanediamine units and/or 2-methyl-1,8-octanediamine units in the total amount of diamine units constituting the semi-aromatic polyamide is preferably 50 to 100 mol%, preferably 60 to 100 mol. %, more preferably 75 to 100 mol %, even more preferably 90 to 100 mol %. When the content of 1,9-nonanediamine units and/or 2-methyl-1,8-octanediamine units in the total amount of diamine units constituting the semiaromatic polyamide is within the above range, the heat resistance is further improved. and excellent chemical resistance can be expected.

When 1,9-nonanediamine and 2-methyl-1,8-octanediamine are used together, the molar ratio of 1,9-nonanediamine:2-methyl-1,8-octanediamine is 99:1 to 1:99. It is preferably 95:5 to 5:95, more preferably 90:10 to 10:90. When the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is within the above range, the reaction with the chain extender (B) proceeds well, and the obtained polyamide resin is excellent. Heat resistance and durability (fatigue resistance) can be expected.

In addition, the semi-aromatic polyamide may contain structural units derived from other than aliphatic diamines, such as aromatic diamines, as diamine units as long as the effects of the present invention are not impaired. 1 type of structural units derived from other than these aliphatic diamines may be contained, and 2 or more types may be contained.
The content of structural units derived from other than the aliphatic diamine in the diamine unit is preferably 30 mol% or less, more preferably 20 mol% or less, further preferably 10 mol% or less, Even more preferably, it is 5 mol % or less.

(aromatic dicarboxylic acid unit)
As the aromatic dicarboxylic acid unit, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6- Aromatics derived from naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenic acid, 4,4'-biphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, etc. A dicarboxylic acid unit may be mentioned.
The semi-aromatic polyamide is a group consisting of terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid from the viewpoint that the effects of the present invention are exhibited more remarkably. It preferably contains a dicarboxylic acid unit derived from at least one selected from, and from the viewpoint of further improving heat resistance, derived from at least one selected from the group consisting of terephthalic acid and 2,6-naphthalenedicarboxylic acid. More preferably, it contains a dicarboxylic acid unit.
These aromatic dicarboxylic acid units may be used singly or in combination of two or more.

From the viewpoint of heat resistance and mechanical strength, the semi-aromatic polyamide contains 30 moles of dicarboxylic acid units derived from at least one selected from the group consisting of terephthalic acid and 2,6-naphthalenedicarboxylic acid with respect to all dicarboxylic acid units. % or more, more preferably 30 to 100 mol%, more preferably 50 to 100 mol%, even more preferably 70 to 100 mol%, even more preferably 90 to 100 mol%, containing 100 mol% You may

In addition, the semi-aromatic polyamide may contain, as dicarboxylic acid units, structural units derived from other than aromatic dicarboxylic acids such as aliphatic dicarboxylic acids, as long as the effects of the present invention are not impaired. 1 type of structural units derived from other than these aromatic dicarboxylic acids may be contained, and 2 or more types may be contained.
Examples of aliphatic dicarboxylic acids include direct acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and dimethylmalonic acid. chain aliphatic dicarboxylic acids;
Branched aliphatic dicarboxylic acids such as 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid;
alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid;
The content of structural units derived from other than the aromatic dicarboxylic acid in the dicarboxylic acid unit is preferably 30 mol% or less, more preferably 20 mol% or less, and further preferably 10 mol% or less. It is preferably 5 mol % or less, and more preferably 5 mol % or less.

The content of units derived from the aliphatic diamine having 4 to 18 carbon atoms is preferably 25 to 55 mol%, more preferably 35 to 55 mol%, based on all structural units constituting the semiaromatic polyamide.
The content of units derived from the content of the aromatic dicarboxylic acid is preferably 15 to 55 mol %, more preferably 25 to 55 mol %, relative to all structural units constituting the semiaromatic polyamide.
The total content of units derived from the aliphatic diamine having 4 to 18 carbon atoms and the aromatic dicarboxylic acid is preferably 40 to 100 mol%, more preferably 60 to 100 mol%, with respect to all structural units constituting the semiaromatic polyamide. is more preferable, 70 to 100 mol% is more preferable, and it may be 90 mol% or more, or even 100 mol%.

(other units)
Moreover, the semi-aromatic polyamide may contain units other than the diamine unit and the dicarboxylic acid unit within a range that does not impair the effects of the present invention. Other units include, for example, polycarboxylic acid units, aminocarboxylic acid units and lactam units.
Examples of polyvalent carboxylic acid units include structural units derived from trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid. These polyvalent carboxylic acid units can be contained within a range in which melt molding is possible.
Examples of aminocarboxylic acid units include structural units derived from lactams such as caprolactam and lauryllactam; aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid.
Examples of lactam units include structural units derived from ε-caprolactam, enantholactam, undecanelactam, lauryllactam, α-pyrrolidone, α-piperidone, and the like.
The content of other units is preferably 30 mol % or less, more preferably 10 mol % or less, relative to all structural units constituting the semi-aromatic polyamide.

Typical semi-aromatic polyamides containing diamine units mainly composed of aliphatic diamine units and dicarboxylic acid units mainly composed of aromatic dicarboxylic acid units include polytetramethylene terephthalamide (polyamide 4T), poly Pentamethylene terephthalamide (polyamide 5T), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), poly(2-methyloctamethylene) terephthalamide (polyamide M8T), polynonamethylene terephthalamide/ Poly(2-methyloctamethylene) terephthalamide copolymer (polyamide 9T/M8T), polynonamethylene naphthalene dicarboxamide (polyamide 9N), poly(2-methyloctamethylene) naphthalene dicarboxamide (polyamide M8N), polynonamethylene naphthalene Carboxamide/poly(2-methyloctamethylene) naphthalene dicarboxamide copolymer (polyamide 9N/M8N), polydecamethylene terephthalamide (polyamide 10T), polyhexamethylene isophthalamide (polyamide 6I), copolymer of polyamide 6I and polyamide 6T coalescence (polyamide 6I/6T), copolymer of polyamide 66, polyamide 6I and polyamide 6T (polyamide 66/polyamide 6I/6T), copolymer of polyamide 6T and polyundecaneamide (polyamide 11) (polyamide 6T/ 11), a copolymer of polyamide 6T and polyamide 10T (polyamide 6T/10T), and a copolymer of polyamide 10T and polyundecaneamide (polyamide 11) (polyamide 10T/11).

<< terminal blocking agent >>
In this embodiment, the polyamide contained in the polymer block (A) may contain structural units derived from a terminal blocking agent.
The unit derived from the terminal blocking agent is preferably 1.0 to 10 mol% with respect to the diamine unit, more preferably 2.0 to 7.5 mol%, 2.5 to 6.5 More preferably, it is mol %.
Units derived from the terminal blocking agent can be adjusted to the desired range by adding the terminal blocking agent to the diamine at the time of charging the polymerization raw material so as to have the above desired range. Considering that the monomer components volatilize during polymerization, the amount of the terminal blocking agent charged when charging the polymerization raw material is finely adjusted so that the desired amount of units derived from the terminal blocking agent is introduced into the resulting resin. It is desirable to In addition, the polymer constituting the polymer block (A) may be charged with a terminal functionalizing agent described later and a terminal blocking agent within the above desired range. In addition, when conducting a chain extension reaction between the polymer constituting the polymer block (A) and a chain extension agent described later, the terminal blocking agent can be added so as to be within the above desired range.

As a method for determining the content of units derived from the terminal blocking agent in the polyamide, for example, as shown in JP-A-07-228690, the solution viscosity is measured, and the relational expression between this and the number average molecular weight from which the total amount of terminal groups is calculated, and the amount of amino groups and the amount of carboxyl groups obtained by titration are subtracted from this.
A monofunctional compound having reactivity with a terminal amino group or a terminal carboxyl group can be used as the terminal blocking agent. Specific examples include monocarboxylic acids, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, and monoamines. From the viewpoint of reactivity and stability of the terminal to be blocked, monocarboxylic acid is preferable as the terminal blocking agent for the terminal amino group, and monoamine is preferable as the terminal blocking agent for the terminal carboxyl group. From the standpoint of ease of handling, etc., monocarboxylic acids are more preferable as terminal blocking agents.

The monocarboxylic acid used as the terminal blocking agent is not particularly limited as long as it has reactivity with an amino group. Examples of monocarboxylic acids include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. cyclopentanecarboxylic acid, cyclohexanecarboxylic acid and other alicyclic monocarboxylic acids; benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid and other aromatic monocarboxylic acids and any mixture thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, and stearic acid are preferred in terms of reactivity, stability of blocked ends, and price. , and benzoic acid are preferred.

The monoamine used as the terminal blocking agent is not particularly limited as long as it has reactivity with carboxyl groups. Examples of monoamines include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine; alicyclic monoamines; aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; arbitrary mixtures thereof; Among these, at least one selected from butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline is preferable from the viewpoints of reactivity, high boiling point, stability of capped ends, price, and the like.

<<Method for producing polyamide>>
When the polyamide is a semi-aromatic polyamide containing a dicarboxylic acid unit and a diamine unit, the semi-aromatic polyamide can be obtained, for example, by using a dicarboxylic acid and a diamine as raw materials and using a melt polymerization method, a solid phase polymerization method, or a melt extrusion polymerization method. It can be produced by a method such as Specifically, a semi-aromatic polyamide can be produced as follows.
First, a diamine, a dicarboxylic acid, and optionally an aminocarboxylic acid, a lactam, a catalyst, a terminal blocking agent, etc. are mixed to produce a nylon salt. Next, the produced nylon salt is heated to a temperature of 200 to 250° C. and heat-polymerized to obtain a semi-aromatic polyamide as a prepolymer.
Furthermore, the molecular weight of the semi-aromatic polyamide can be adjusted to a desired value by solid-phase polymerizing the prepolymer or increasing the degree of polymerization using a melt extruder.
When the step of increasing the degree of polymerization is performed by a solid phase polymerization method, it is preferably performed under reduced pressure or under inert gas flow. and can effectively suppress coloring and gelation. Further, when the step of increasing the degree of polymerization is performed by a melt extruder, the polymerization temperature is preferably 370° C. or less, and when the polymerization is performed under such conditions, a semi-aromatic polyamide with little decomposition and little deterioration can be obtained. be done.

Examples of catalysts that can be used in producing semi-aromatic polyamides include phosphoric acid, phosphorous acid, hypophosphorous acid, salts or esters thereof, and the like. Examples of the above salts or esters include phosphoric acid, phosphorous acid, or hypophosphorous acid and potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony, and the like. Salt with metal; Ammonium salt of phosphoric acid, phosphorous acid or hypophosphite; Ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, octadecyl ester of phosphoric acid, phosphorous acid or hypophosphorous acid , decyl ester, stearyl ester, phenyl ester, and the like.
The amount of the catalyst used is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, relative to 100% by mass of the total mass of the raw materials for the semi-aromatic polyamide. The amount of catalyst used is preferably 1.0% by mass or less, more preferably 0.5% by mass or less. If the amount of the catalyst used is at least the above lower limit, the polymerization proceeds more favorably.

<<Terminal amino group content (before terminal conversion)>>
In this embodiment, the polyamide can be adjusted to have a desired functional group or functional group amount at the end of the polyamide by using a terminal functionalizing agent to be described later.
On the other hand, the term "terminal amino group content" as used herein refers to the terminal amino group content in the polyamide before terminal conversion with a terminal functionalizing agent.
The polyamide before terminal conversion has a terminal amino group content ([NH ₂ ]), which is the content of terminal amino groups, of preferably 1 to 50 μmol/g, more preferably 1 to 40 μmol/g, and still more preferably 1 to 30 μmol/g, more preferably 1 to 20 μmol/g.
The terminal amino group content ([NH ₂ ]) as used herein refers to the amount of terminal amino groups contained in 1 g of the polyamide (unit: μmol), and can be determined by a neutralization titration method using an indicator. .

<<Terminal carboxyl group content (before terminal conversion)>>
The polyamide before terminal conversion has a terminal carboxyl group content ([COOH]), which is the content of terminal carboxyl groups, of preferably 50 to 600 μmol / g, more preferably 60 to 600 μmol / g, more preferably 70 to 600 μmol/g, more preferably 75-600 μmol/g.
The terminal carboxyl group content ([COOH]) as used herein refers to the amount (unit: μmol) of terminal carboxyl groups contained in 1 g of polyamide, and can be obtained by potentiometric titration.

<<melting point>>
The melting point of the polyamide is preferably 230°C or higher, more preferably 240°C or higher, and even more preferably 250°C or higher. Although the upper limit of the melting point of the polyamide is not particularly limited, it is preferably 320° C. or less from the viewpoint of moldability. If the melting point of the polyamide is 230°C or higher, the heat resistance of the polyamide-based resin of the present embodiment can be further improved.
In the present invention, the melting point can be obtained as the peak temperature of the melting peak that appears when the temperature is raised at a rate of 10° C./min using a differential scanning calorimetry (DSC) apparatus. More specifically, it can be obtained by the method described in the examples below.

<<molecular weight>>
The number average molecular weight of the polymer block (A) is preferably 2,000 to 10,000, more preferably 2,200 to 10,000, even more preferably 2,400 to 8,000, still more preferably 2,500 to 7,000. If it is within the above numerical range, the reactivity between the polymer block (A) and the chain extender (B) is excellent, and the heat resistance, moldability (moldability) and durability (fatigue resistance) of the polyamide resin can be further improved.
The weight average molecular weight of the polymer block (A) is preferably 8,000 to 50,000, more preferably 9,000 to 45,000, still more preferably 10,000 to 40,000, still more preferably 10,000. 000 to 35,000, more preferably 10,000 to 30,000. If it is within the above numerical range, the reactivity between the polymer block (A) and the chain extender (B) is excellent, and the heat resistance, moldability (moldability) and durability (fatigue resistance) of the polyamide resin can be further improved.
In the present invention, the number average molecular weight and weight average molecular weight can be measured by gel permeation chromatography, and more specifically, they are values measured by the method described in Examples.

<< terminal functionalizing agent >>
In this embodiment, a terminal functionalizing agent can be used to form a polymer block (A) having a desired functional group or functional group amount at the terminal of the polyamide.
For example, the end of the polyamide can be converted by reacting the above-described polyamide prepolymer with a terminal functionalizing agent. By adjusting the terminal of the polymer block (A) to have a desired functional group or amount of functional groups, the polymer block (A) and the chain extender (B) can be better bonded. Units derived from the terminal functionalizing agent shall be included in the polymer block (A).

In addition, when the polyamide obtained by the method for producing a polyamide described above has a desired functional group or amount of functional groups, the terminal functionalizing agent may not be used. That is, in this case, a polyamide system in which the polymer block (A) and the chain extender (B) are well bonded by reacting the polyamide and the chain extender (B) without using a terminal functionalizing agent resin can be obtained.
The adjustment of the amount of active terminal functional groups of the polyamide, which will be described later, can be performed by adjusting the amount of carboxyl groups and the amount of amino groups contained in the reaction raw materials in the production of the polyamide, for example.
When a terminal functionalizing agent is used, the terminal of the polyamide can be adjusted to have a desired functional group or functional group amount by adding the terminal functionalizing agent when polymerizing the polymer constituting the polymer block (A). can. In addition, the terminal of the polyamide can be adjusted to a desired functional group or functional group amount by adding a terminal functionalizing agent together with a terminal blocking agent to the polymer constituting the polymer block (A). Further, when conducting a chain extension reaction between the polymer constituting the polymer block (A) and a chain extender described later, a terminal functionalizing agent is added to make the terminal of the polyamide a desired functional group or functional group amount. It can also be adjusted.

The terminal functionalizing agent is not limited as long as it does not impair the effects of the present invention, and hydroxyl group, carboxyl group, amino group, epoxy group, mercapto group, sulfonyl group, halogen atom, vinyl group, vinylidene group at the end of polyamide. and those into which a functional group can be introduced.

In this embodiment, it is preferable to use a dicarboxylic acid and a diamine as the terminal functionalizing agent.
Dicarboxylic acids that can be used as end-functionalizing agents include aliphatic dicarboxylic acids and aromatic dicarboxylic acids.
Examples of aliphatic dicarboxylic acids include direct acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and dimethylmalonic acid. chain aliphatic dicarboxylic acids;
Branched aliphatic dicarboxylic acids such as 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid;
alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid;
Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, diphenic acid, 4,4′-biphenyldicarboxylic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, 1, 2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8- Naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,5-furandicarboxylic acid acid, 3,4-furandicarboxylic acid and the like.

Diamines that can be used as end-functionalizing agents include aliphatic diamines and aromatic diamines.
Examples of aliphatic diamines include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octane Diamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15-pentadecanediamine , 1,16-hexadecanediamine, 1,17-heptadecanediamine, 1,18-octadecanediamine and other linear aliphatic diamines;
1,2-propanediamine, 1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, 1-ethyl-1,4-butanediamine, 2-ethyl-1,4- Butanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2-methyl-1,3- Propanediamine, 2-methyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2 -ethyl-1,5-pentanediamine, 2-propyl-1,5-pentanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2 ,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6- Hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-ethyl-1,6-hexanediamine, 2-propyl-1,6-hexanediamine, 2,4-diethyl-1,6- Hexanediamine, 2-ethyl-1,7-heptanediamine, 2-propyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 1,3 -dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4 ,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine , 2-ethyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, 5-methyl-1,9-nonanediamine, and other branched aliphatic diamines;
1,2-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5 - Alicyclic compounds such as trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, and bis(aminopropyl)piperazine diamine; and the like.
Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,4 '-diaminodiphenyl ether, 4,4'-methylenedi-2,6-diethylaniline and the like.
The terminal functionalizing agent may be used alone or in combination of two or more.

<< Active terminal functional group content >>
In the present invention, the "active terminal functional group content" is the content of the active terminal functional groups of the polymer block (A) contained in the polyamide resin, and the total content of the active terminal functional groups of the polyamide is It becomes the active terminal functional group content of coalescing block (A). The "active terminal functional group" is a functional group that exhibits reactivity with the chain extender (B), and examples thereof include an amino group and a carboxyl group.
When the terminal of the polyamide is converted using a terminal functionalizing agent, the "active terminal functional group content" is the content of the active terminal functional group after the terminal functional group is converted. For example, when a polyamide having terminal amino groups is converted to carboxyl groups using a terminal functionalizing agent, the total content of terminal carboxyl groups after conversion and terminal amino groups that have not been converted is the polymer block (A ) is the active terminal functional group content.

The active terminal functional group content of the polymer block (A) is preferably 75-600 μmol/g, more preferably 90-560 μmol/g, still more preferably 100-520 μmol/g. If the active terminal functional group content is 75 μmol/g or more, the reactivity between the polymer block (A) and the chain extender (B) is excellent, and the moldability (moldability) and durability (resistance) of the polyamide resin are improved. fatigue) can be further improved. Further, when the active terminal functional group content is 600 μmol/g or less, the heat resistance of the polyamide-based resin can be further improved.
Active terminal functional group content as used herein refers to the amount of active terminal functional groups (unit: μmol) contained in 1 g of polyamide (polyamide after conversion when a terminal functionalizing agent is used), and an indicator is used. It can be determined by the neutralization titration method and potentiometric titration method used. Specifically, it can be calculated by the method described in Examples described later.

The content of the polymer block (A) in the polyamide resin is not particularly limited as long as it is 91.0% by mass or more and less than 99.0% by mass, while maintaining the heat resistance of the resulting polyamide resin. , From the viewpoint of imparting moldability and excellent fatigue resistance, preferably 92.0% by mass or more and 98.7% by mass or less, more preferably 93.5% by mass or more and 98.5% by mass or less, still more preferably 95% by mass 0% by mass or more and 98.3% by mass or less.

<Chain extender (B)>
The chain extender (B) in this embodiment is a compound having two active terminal functional groups, specifically terminal amino groups or terminal carboxyl groups, of the polymer block (A). ₁ -A'-Y can be represented as ₁ .
_Y1 includes maleimide group, isocyanate group, oxazinone group, oxazolinone group, cyclic anhydride group, caprolactam group, oxazolyl group, oxazine group, imidazoline group, aziridine group and epoxy group.
A′ includes an alkylene group, a cycloalkylene group, an arylene group, or a single covalent bond between two Y ₁ s. Such alkylene group, cycloalkylene group and arylene group may have a substituent.

Examples of the chain extender (B) in which Y ₁ is a cyclic anhydride group include ethylenetetracarboxylic dianhydride, pyromellitic dianhydride, and 3,3′,4,4′-biphenyltetracarboxylic dianhydride. , 1,4,5,8-naphthalenetetracarboxylic dianhydride, perylenetetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 1,2,3,4 -cyclobutanetetracarboxylic dianhydride, hexafluoroisopropylidenebisphthalic dianhydride, 9,9-bis(trifluoromethyl)xanthenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone Tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride Anhydride, 3,3′,4,4′-diphenyl ether tetracarboxylic acid dianhydride.

Examples of the chain extender (B) in which Y ₁ has an epoxy group include bisphenol A diglycidyl ether (DGEBA) and (alicyclic) hydrogenated derivatives thereof, bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, or hydroquinone diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, polyethylene glycol diglycidyl ether, Examples include diglycidyl esters of dicarboxylic acids such as polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A polyethylene glycol diglycidyl ether, and diglycidyl terephthalate. They preferably have a molecular weight of 700 or less.

Examples of the chain extender (B) in which Y ₁ has an isocyanate group include terephthaloyl biscaprolactam and isophthaloyl biscaprolactam.

Examples of chain extenders (B) wherein Y ₁ is an oxazolyl group or an oxazine group include bisoxazoline, bisoxazine, wherein A' is a single covalent bond; A' is an arylene group, such as a 1,2-phenylene group; 1,3-bis(4,5-dihydro-2-oxazolyl)benzene, 1,4-bis(4,5-bis(4,5- dihydro-2-oxazolyl)benzene and the like.

Chain extenders (B) in which Y ₁ is an imidazoline group include bisimidazolines and compounds described, for example, in EP0739924.
Chain extenders (B) in which Y ₁ is an oxazinone group or an oxazolinone group include bis(benzoxazinone), bisoxazinone, bisoxazolinone, and compounds described, for example, in EP 0581641.

Examples of the chain extender (B) in which Y ₁ is an aziridine group include 1,1′-isophthaloylbis(2-methylaziridine).

In this embodiment, the chain extender (B) preferably contains an oxazolyl group. More specifically, the chain extender (B) is 1,3-bis(4, 5-dihydro-2-oxazolyl)benzene or 1,4-bis(4,5-dihydro-2-oxazolyl)benzene are more preferred.

Although the number average molecular weight of the chain extender (B) is not particularly limited, it is preferably 100-700, more preferably 150-400, still more preferably 200-300.

When polymer block (A) has a terminal carboxyl group and chain extender (B) is 1,4-bis(4,5-dihydro-2-oxazolyl)benzene, the resulting reaction product is Structure of :
-OC(O)-P-C(O)-OR ¹ -NHC(O)-A'-C(O)NH-R ¹ -
(Wherein, P represents the remainder of the polymer block (A) excluding both terminal carboxyl groups, R ¹ is an ethylene group, and A' is a phenylene group.) .

<Method for producing polyamide resin>
In the polyamide-based resin of the present embodiment, for example, the polymer constituting the polymer block (A) and the chain extender (B) are combined in the absence of the terminal functionalizing agent and the terminal blocking agent. It can be produced by dry blending and melt-kneading the mixture. Alternatively, the polymer constituting the polymer block (A) and the chain extender (B) are dry blended in the presence of the terminal functionalizing agent and/or the terminal blocking agent, and the mixture is melted. A polyamide-based resin can be produced by kneading. Further, the semi-aromatic polyamide, which is the polymer constituting the polymer block (A), is reacted with the terminal functionalizing agent and/or the terminal blocking agent, and then pulverized to obtain the polymer block (A ) may be adjusted, then the chain extender (B) may be added and dry-blended, and the mixture may be melt-kneaded. Further, the semi-aromatic polyamide, which is the polymer constituting the polymer block (A), and the terminal functionalizing agent and/or the terminal blocking agent are charged from the upper hopper of the melt kneader and reacted. Alternatively, the chain extender (B) may be melt-kneaded in stages by adding the chain extender (B) from the side feed port on the downstream side of the extruder.
Methods such as a melt polymerization method, a solid phase polymerization method, a melt extrusion polymerization method, and the like can usually be employed. A melt polymerization method or a melt extrusion polymerization method may be combined with a solid phase polymerization method. As the melt extrusion polymerization method, a method of melt-kneading using a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or the like is preferably employed. Although the melt-kneading conditions are not particularly limited, for example, a method of melt-kneading for about 1 to 60 minutes at a temperature range higher than the melting point of the polyamide by about 0 to 60 ° C. is from the viewpoint that the effects of the present invention are more likely to be expressed. preferable.
The reaction between the polymer constituting the polymer block (A) and the chain extender (B) is usually a ring-opening addition polymerization reaction, and therefore does not produce condensation water.

<Usage ratio>
In the polyamide-based resin of this embodiment, the ratio of the amount of the chain extender (B) used to the polymer block (A) maintains the heat resistance of the obtained polyamide-based resin, while maintaining moldability and excellent fatigue resistance. From the viewpoint of imparting /1.3, more preferably 93.5/6.5 to 98.5/1.5, and even more preferably 95.0/5.0 to 98.3/1.7. In addition, since the total amount of the polymer block (A) and the chain extender (B) is generally reacted, the above-mentioned usage ratio is the content ratio in the polyamide resin.

<Molecular weight of polyamide resin>
The number average molecular weight of the polyamide resin is not particularly limited, but is preferably 4,000 to 15,000, more preferably 5,000 or more and less than 10,000, still more preferably 5,000 to 9,000, and still more It is preferably 5,000 to 8,000. The higher the molecular weight, the better the heat resistance, but the moldability tends to decrease. Within the above numerical range, the heat resistance of the polyamide-based resin can be further improved, and good moldability can be expected.
The weight average molecular weight of the polyamide resin is not particularly limited as long as it is 40,000 to 150,000, preferably 42,000 to 150,000, more preferably 43,000 to 120,000, still more preferably 45,000 to 100,000, more preferably 50,000 to 90,000. Within the above numerical range, the polyamide-based resin can be expected to exhibit tougher material properties and good moldability.

<Physical properties>
<<melting point>>
The melting point of the polyamide-based resin is generally preferably 230° C. or higher because the molded article obtained using the polyamide-based resin has good thermal stability.
The melting point of the polyamide resin is preferably 235°C or higher, more preferably 240°C or higher. Although the upper limit of the melting point of the polyamide resin is not particularly limited, it is preferably 315° C. or less from the viewpoint of moldability and the like.

<<Melt Viscosity>>
The melt viscosity of the polyamide resin of this embodiment is preferably 50 to 1000 Pa·s, more preferably 60 to 900 Pa·s, and still more preferably 70 to 800 Pa·s.
As used herein, melt viscosity is an index of moldability (moldability). If the melt viscosity is in the range of 50 to 1000 Pa·s, it can be said that the polyamide resin has excellent moldability.
More specifically, the melt viscosity can be determined by the method described in the examples below.

<<Fatigue resistance>>
For the polyamide resin of this embodiment, the time strength under the condition of applying a tensile load, measured according to JIS K 7118: 1995, is preferably ¹⁰ times or more at 30 MPa stress, more preferably 10 times at 40 MPa stress. ⁷ times or more.
As used herein, the time strength is an index of fatigue resistance. If the time strength is 10 ⁷ times or more at a stress of 30 MPa, it can be said that the polyamide resin has excellent fatigue resistance.
More specifically, the time strength can be determined by the method described in the examples below.

[Polyamide resin composition]
As one of the present embodiments, a polyamide resin composition containing the above polyamide resin can be provided.
The polyamide-based resin composition contains additives other than the polyamide-based resin in addition to the polyamide-based resin. Additives include, for example, antioxidants, antiozonants, weather stabilizers, ultraviolet absorbers, hydrolysis stabilizers, fillers, crystal nucleating agents, reinforcing agents, carbon black, pigments, inorganic dyes, organic dyes. , colorants, anti-coloring agents, anti-gelling agents, matting agents, antistatic agents, plasticizers, lubricants, release agents, shrinkage resistance agents, compatibilizers, flame retardants, flame retardant aids, foaming agents, etc. is mentioned.
1 type of these may be contained, and 2 or more types may be contained.
The content of the additive is preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the polyamide resin, more preferably 0.1 to 10 parts by mass, and 0.3 to 5 parts by mass. is more preferable.
Examples of the method of adding the additive include a method of adding during polymerization of the polyamide resin, a method of dry blending with the polyamide resin, and melt kneading.

In this embodiment, the additive is at least one of a nucleating agent, a reinforcing agent, an antioxidant, and a lubricant. fatigue resistance).

Nucleating agents include talc and carbon black. The average particle size of talc is preferably 1-20 μm. The average particle size can be determined by image analysis using electron microscopy. Specifically, the length and breadth of 1000 or more talc particles photographed using a transmission electron microscope are measured, and the average value is taken as the average particle size. When the polyamide-based resin composition of this embodiment contains a nucleating agent, the content thereof is preferably 0.05 to 1.0% by mass with respect to the total mass of the polyamide-based resin composition.

As the reinforcing agent, those having various forms such as fibrous, tabular, needle-like, powdery and cloth-like can be used. Specifically, fibrous fillers such as glass fiber, carbon fiber, aramid fiber, liquid crystal polymer (LCP) fiber, metal fiber; tabular filler such as mica; potassium titanate whisker, aluminum borate whisker, calcium carbonate Acicular fillers such as whiskers, magnesium sulfate whiskers, wollastonite, sepiolite, xonotlite, zinc oxide whiskers; silica, alumina, barium carbonate, magnesium carbonate, aluminum nitride, boron nitride, titanium oxide, potassium titanate, aluminum silicate (kaolin, clay, pyrophyllite, bentonite), calcium silicate, magnesium silicate (attapulgite), magnesium oxide, aluminum borate, calcium sulfate, barium sulfate, magnesium sulfate, asbestos, glass beads, graphite, carbon nanotubes, carbonization Examples include powdery fillers such as silicon, sericite, hydrotalcite, molybdenum disulfide, phenolic resin particles, crosslinked styrene resin particles, and crosslinked acrylic resin particles. These reinforcing agents may be used alone or in combination of two or more.

The surface of the reinforcing agent is coated with silane coupling agents, titanium coupling agents, acrylic resins, urethane resins, and epoxy resins for the purpose of enhancing dispersibility in polyamide resins or enhancing adhesiveness with polyamide resins. It may be surface-treated with a high-molecular-weight compound such as, or other low-molecular-weight compounds.

Among the reinforcing agents described above, at least one selected from the group consisting of fibrous fillers and needle-like fillers is preferable because it is inexpensive and gives a molded article with high mechanical strength. The reinforcing agent is preferably glass fiber from the viewpoint of high strength and low cost, and preferably an acicular filler from the viewpoint of obtaining a molded product with high surface smoothness. As the reinforcing agent, at least one selected from the group consisting of glass fibers, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, and aluminum borate whiskers can be preferably used. At least one selected is more preferably used.

The average fiber length of the glass fiber is preferably 1-10 mm, more preferably 1-7 mm, and still more preferably 2-4 mm. Also, the average fiber diameter of the glass fibers is preferably 6 to 20 μm, more preferably 6 to 15 μm, from the viewpoint of obtaining mechanical strength.
The average aspect ratio of wollastonite is preferably 3 or more, more preferably 5 or more, and still more preferably 10 or more from the viewpoint of obtaining mechanical strength. The average fiber diameter of wollastonite is preferably 0.1 to 15 μm, more preferably 2.0 to 7.0 μm.
The average fiber length, average fiber diameter, and average aspect ratio can be determined by image analysis using electron microscopy.
When the polyamide-based resin composition of this embodiment contains a reinforcing agent, the content thereof is preferably 0.05 to 100 parts by mass with respect to 100 parts by mass of the polyamide-based resin.

Antioxidants include hindered phenol-based antioxidants, hindered amine-based antioxidants, phosphorus-based antioxidants, thio-based antioxidants, and the like.
Commercially available hindered phenol antioxidants can be used, for example, "Adekastab AO-20", "Adekastab AO-50", and "Adekastab AO-80" (trade names, all manufactured by ADEKA Corporation). ; "IRGANOX1010", "IRGANOX1076", "IRGANOX1035", "IRGANOX1098", "IRGANOX245", "IRGANOX259" (trade names, all manufactured by BASF Japan Co., Ltd.); "Sumilizer GA-80" (trade name, Sumitomo Chemical Co., Ltd.) and the like.
As the hindered amine-based antioxidant, HALS, which means Hindered Amine Light Stabilizer, can be used, and examples thereof include "Tinuvin770DF" (trade name, manufactured by BASF Japan Ltd.) .
Phosphorus-based antioxidants include, for example, phosphites, phosphonites, and oxaphosphaphenanthrene oxide. Commercially available phosphorus antioxidants can be used, for example, "IRGAFOS168" (trade name, manufactured by BASF Japan Ltd.), "Hostanox P-EPQ" (trade name, manufactured by Clariant Japan Ltd.), " GSY-P101” (trade name, manufactured by Sakai Chemical Industry Co., Ltd.) and the like.
Examples of thio-based antioxidants include "Sumilizer TP-D", an organic sulfur-based secondary antioxidant manufactured by Sumitomo Chemical Co., Ltd., and the like.
Examples of other antioxidants and stabilizers used for similar purposes include UV inhibitors such as "Tinuvin 312" manufactured by BASF Japan Co., Ltd.), amine antioxidants such as "Naugard 445" manufactured by Addivant Multifunctional stabilizers such as "Nylostab S-EED" from Clariant Chemicals, Inc., or mineral stabilizers such as copper-based stabilizers can also be used.
Examples of mineral stabilizers include copper halides and copper acetate. Second, other metals such as silver can optionally be considered, but are known to be less effective. These copper-containing compounds are usually combined with alkali metal halides, especially potassium halides.
When the polyamide resin composition of the present embodiment contains an antioxidant, the content thereof is preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyamide resin, and 0.1 to More preferably, it is 3 parts by mass.

Examples of lubricants include amides of higher fatty acids such as stearic acid and montanic acid, esters thereof, and metal salts thereof such as calcium, which are generally added to resins as internal or external lubricants.
When the polyamide-based resin composition of the present embodiment contains a lubricant, the content thereof is preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyamide-based resin, and 0.1 to 3 parts by mass. Part is more preferred.

<Method for producing polyamide resin composition>
The method for producing the polyamide resin composition is not particularly limited, and a method capable of uniformly mixing the polyamide resin and the above additives can be preferably employed. For mixing, a method of melt-kneading using a single-screw extruder, twin-screw extruder, kneader, Banbury mixer, or the like is preferably adopted. Although the melt-kneading conditions are not particularly limited, for example, a method of melt-kneading for about 1 to 60 minutes at a temperature in the range of about 0 to 60° C. higher than the melting point of the polyamide resin can be mentioned.

[Molding]
As one of the present embodiments, a molded article made of the polyamide resin or the polyamide resin composition can be used.
The molded article of this embodiment can be used as electrical and electronic parts, automobile parts, industrial parts, fibers, films, sheets, household goods, and various other molded articles of any shape and purpose.

<Application>
The polyamide-based resin and polyamide-based resin composition of the present embodiment are excellent in heat resistance, moldability, and durability (fatigue resistance), so they can be used in a wide range of fields where these physical properties are required. For example, the polyamide-based resin and polyamide-based resin composition of the present embodiment can be used for electric and electronic parts, automobile parts, industrial material parts, industrial parts, daily necessities, household goods, sports parts, leisure parts, medical parts, etc. It can be widely used as a material for various parts of

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

<Measurement and evaluation method>
Various physical properties were measured or evaluated by the following methods.

<<molecular weight>>
The semi-aromatic polyamides produced in the synthesis examples used as the polymer block (A), and the polyamide-based resins and polyamide-based resin compositions obtained in the examples and comparative examples were used as samples, respectively, and subjected to gel permeation chromatography (GPC). The number average molecular weight (Mn), weight average molecular weight (Mw), peak top molecular weight (Mp) and molecular weight distribution (Mw/Mn) were obtained as standard polymethyl methacrylate equivalent molecular weights.
An HFIP solution in which 0.85 g of sodium trifluoroacetate was dissolved in 1 kg of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) was used as an eluent. A sample of 1.5 mg in terms of resin was weighed and dissolved in 3 mL of the above eluent. The solution was passed through a 0.4 μm membrane filter to prepare a measurement sample. The measurement conditions were as follows.
(Measurement condition)
Apparatus: HLC-8320GPC (manufactured by Tosoh Corporation)
Column: Two TSK gel Super HM-H (manufactured by Tosoh Corporation) were connected in series.
Eluent: 0.085% sodium trifluoroacetate/HFIP solution Flow rate: 0.5 mL/min (reference column: 0.25 mL/min)
Sample injection volume: 30 μL
Column temperature: 40°C
Standard polymethyl methacrylate: Shodex Standard M-75 from Showa Denko K.K., Polymethacrylate from Agilent Technologies, Inc. Molecular weight 1010 and molecular weight 535
Detector: UV (254 nm) detector, UV (210 nm) detector

<<Measurement of Terminal Amino Group Content ([NH ₂ ])>>
Using the semi-aromatic polyamide produced in Synthesis Example as a sample, 1 g of the sample was dissolved in 35 ml of phenol and mixed with 3 ml of methanol to prepare a sample solution. Using thymol blue as an indicator, titration was performed using 0.01 or 0.1 N HCl aqueous solution to measure terminal amino group content ([NH ₂ ], unit: μmol/g).

<<Measurement of terminal carboxyl group content ([COOH])>>
Using the semi-aromatic polyamide produced in Synthesis Example as a sample, 0.5 g of the sample was dissolved in 40 ml of ortho-cresol to prepare a sample solution. Using a potentiometric titrator, titration using 0.01 or 0.1N KOH/EtOH solution was performed to measure terminal carboxyl group content ([COOH], unit: μmol/g).
(Measurement condition)
Measuring device: MCU-710M/S (manufactured by Kyoto Electronics Industry Co., Ltd.)
Measuring unit: AT-710
Main control unit: MCU-710

<< Active terminal functional group content >>
Using the respective functional group amounts [NH ₂ ] and [COOH] of the semi-aromatic polyamide obtained from the measurement of the terminal amino group content and the measurement of the terminal carboxyl group content, the polymer block (A) is obtained from the following formula. The active terminal functional group content was calculated.
<formula>:
Active terminal functional group content (μmol/g) = ([NH ₂ ]+[COOH])

<<melting point>>
The semi-aromatic polyamides produced in Synthesis Examples and the polyamide resins or polyamide resin compositions obtained in Examples and Comparative Examples were used as samples, respectively, and their melting points were measured by a differential scanning calorimeter manufactured by Mettler Toledo Co., Ltd. Measured using a "DSC822e".
The melting point was measured according to ISO11357-3 (2nd edition, 2011). Specifically, in a nitrogen atmosphere, the sample was heated from 30 ° C. to 340 ° C. at a rate of 10 ° C./min, held at 340 ° C. for 5 minutes to completely melt the sample, and then heated at 10 ° C./min. Cooled to 50°C at speed and held at 50°C for 5 minutes. The peak temperature of the melting peak that appears when the temperature is again raised to 340°C at a rate of 10°C/min is the melting point (°C), and if there are multiple melting peaks, the peak temperature of the highest melting peak is the melting point (°C). did.

<<Melt Viscosity>>
Each component was premixed in the ratio (parts by mass) shown in Table 3 or Table 4, and 5 to 20 g of the prepared mixed sample was added to the polymer using a desktop small kneader manufactured by Xplore Instruments ("Xplore MC15"). The mixture was melt-kneaded at a cylinder temperature 10 to 50° C. higher than the melting point of the block (A) for 2 to 15 minutes, extruded, cooled and cut to produce a polyamide resin or a polyamide resin composition in the form of pellets.
Pellets of the polyamide-based resin or polyamide-based resin composition produced by the above method were measured using a capillograph (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 280-340 ° C. and a shear rate of 121.6 sec ^-1 (capillary: inner diameter The melt viscosity (Pa·s) was measured under the conditions of 1.0 mm×10 mm length and extrusion speed of 10 mm/min, and used as an index of moldability.

<<Evaluation of fatigue resistance by tensile fatigue test>>
Each component was premixed in the ratio (parts by mass) shown in Table 3 or Table 4, and 5 to 20 g of the prepared mixed sample was added to the polymer using a desktop small kneader manufactured by Xplore Instruments ("Xplore MC15"). After melt-kneading for 2-15 minutes at a cylinder temperature 10-50°C higher than the melting point of the block (A), the mold temperature of the T-runner mold of the injection molding machine is 120-200°C and the injection pressure is 0.1-7.0 bar. A small test piece type 1BA (2 mm thickness, total length 75 mm, parallel portion length 30 mm, parallel portion width 5 mm) for tensile fatigue evaluation was prepared under the conditions of .
Using the test piece prepared above, according to JIS K 7118: 1995, using a tensile fatigue tester (tensile fatigue tester FT-5 manufactured by Saginomiya Seisakusho Co., Ltd.), 23 ° C., a sine wave with a frequency of 30 Hz The time strength was measured under the condition that a tensile load was applied at , and evaluated according to the following criteria (the number of times of loading at a constant stress). A and B pass, C and D fail.
A: 10 ⁷ times or more at 40 MPa stress B: 10 ⁷ times or more at 30 MPa stress C: 10 ⁶ times or more at 30 MPa stress D: Less than 10 ⁶ times at 30 MPa stress

<Polymer block (A)>
PA-1 to 9 produced in the following Synthesis Examples were used as constituents of the polymer block (A).
(Synthesis example 1)
Preparation of semi-aromatic polyamide (PA-1) 1059.9 g (6.38 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 85/15)918. 0 g (5.80 mol), 1.98 g of sodium hypophosphite monohydrate (0.1% by mass with respect to the total mass of the raw materials), and 770 mL of distilled water were placed in an autoclave having an internal volume of 5 L and purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-1”.

(Synthesis example 2)
Preparation of semi-aromatic polyamide (PA-2) 1043.8 g (6.28 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 85/15) 965. 5 g (6.10 mol), 2.01 g of sodium hypophosphite monohydrate (0.1% by mass relative to the total mass of raw materials), and 782 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-2”.

(Synthesis Example 3)
Preparation of semi-aromatic polyamide (PA-3) 1016.7 g (6.12 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 85/15)949. 7 g (6.00 mol), 1.97 g of sodium hypophosphite monohydrate (0.1% by mass with respect to the total mass of raw materials), and 766 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-3”.

(Synthesis Example 4)
Preparation of semi-aromatic polyamide (PA-4) 1006.7 g (6.06 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 85/15)949. 7 g (6.00 mol), 1.96 g of sodium hypophosphite monohydrate (0.1% by mass with respect to the total mass of raw materials), and 762 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-4”.

(Synthesis Example 5)
Preparation of semi-aromatic polyamide (PA-5) 1043.8 g (6.28 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 50/50)965. 5 g (6.10 mol), 2.00 g of sodium hypophosphite monohydrate (0.1% by mass relative to the total mass of raw materials), and 782 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-5”.

(Synthesis Example 6)
Preparation of semi-aromatic polyamide (PA-6) 992.5 g (5.97 mol) of terephthalic acid, 999.4 g (5.80 mol) of 1,10-decanediamine, sodium hypophosphite monohydrate1. 99 g (0.1% by mass with respect to the total mass of raw materials) and 775 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-6”.

(Synthesis Example 7)
Preparation of a semi-aromatic polyamide (PA-7) 1116.4 g (6.72 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 50/50)886. 4 g (5.60 mol), 2.00 g of sodium hypophosphite monohydrate (0.1% by mass relative to the total mass of raw materials), and 780 mL of distilled water were placed in an autoclave having an internal volume of 5 L, and the autoclave was purged with nitrogen. . The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-7”.

(Synthesis Example 8)
Preparation of semi-aromatic polyamide (PA-8) 1015.6 g (6.11 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 80/20)988. 2 g (6.24 mol), 21.2 g (0.17 mol) of benzoic acid, 2.02 g of sodium hypophosphite monohydrate (0.1% by weight relative to the total weight of raw materials) and 788 mL of distilled water was placed in an autoclave with an internal volume of 5 L and purged with nitrogen. The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-8”.

(Synthesis Example 9)
Preparation of semi-aromatic polyamide (PA-9) 1017.6 g (6.13 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (molar ratio 50/50)988. 2 g (6.24 mol), 18.2 g (0.15 mol) of benzoic acid, 2.02 g of sodium hypophosphite monohydrate (0.1% by weight relative to the total weight of raw materials) and 788 mL of distilled water was placed in an autoclave with an internal volume of 5 L and purged with nitrogen. The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 3 hours. At this time, the pressure inside the autoclave increased to 2.0 MPa. Heating was continued for 2 hours while maintaining the pressure at 2.0 MPa, and the reaction was allowed to proceed while removing steam gradually. Further reacting for 1 hour, a prepolymer was obtained. The resulting prepolymer was dried at 120° C. under reduced pressure for 24 hours and pulverized to a particle size of 1 mm or less. This was solid-phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polymer block (A). This polymer block (A) is abbreviated as semi-aromatic polyamide “PA-9”.

PA-1 to PA-9 were evaluated for various physical properties as described above. Table 1 shows the results.
Note that the notations in Table 1 are as follows.
"n/i" indicates the molar ratio of 1,9-nonanediamine, which is a linear diamine unit, to 2-methyl-1,8-octanediamine, which is a branched diamine unit.
In PA-6, the linear diamine unit represents 1,10-decanediamine.
"[ _NH2 ]" indicates the terminal amino group content.
"[COOH]" indicates terminal carboxyl group content.

<Chain extender (B)>
The following were used as a chain extender (B).
・ 1,3-PBO: 1,3-bis (4,5-dihydro-2-oxazolyl) benzene, manufactured by Tokyo Chemical Industry Co., Ltd. ・ 1,4-PBO: 1,4-bis (4,5-dihydro- 2-oxazolyl) benzene, manufactured by Tokyo Chemical Industry Co., Ltd.

Table 2 shows the physical properties of the chain extender (B).
Note that the notations in Table 2 are as follows.
"Mn" indicates the number average molecular weight (catalog value).
"Active terminal functional group content" indicates a value obtained from the following <formula>.
<formula>:
Active terminal functional group content (μmol/g) = 2/(chain extender molecular weight) x 1,000,000

<Examples 1 to 9, Comparative Examples 1 to 6>
(Example 1)
Semi-aromatic polyamide "PA-1" as the polymer block (A), 1,3-bis (4,5-dihydro-2-oxazolyl) benzene (1,3-) as the chain extender (B) PBO) was mixed in advance at the ratio shown in Table 3, and 5 to 20 g of the prepared mixed sample was added to the polymer block (A) using a desktop small kneader ("Xplore MC15") manufactured by Xplore Instruments. The mixture was melt-kneaded at a cylinder temperature 10 to 50° C. higher than the melting point for 2 to 15 minutes, extruded, cooled and cut to produce a pellet-like polyamide resin or polyamide resin composition. A test piece for tensile evaluation was prepared by melting and kneading a mixed sample prepared in the same manner as above, and then tensile under the conditions of a mold temperature of 120 to 200 ° C. and an injection pressure of 0.1 to 7.0 bar. A small test piece type 1BA (2 mm thickness, total length of 75 mm, parallel portion length of 30 mm, parallel portion width of 5 mm) for fatigue evaluation was produced.

(Example 2)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-2" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Example 3)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-3" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Example 4)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-4" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Example 5)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-5" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Example 6)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-6" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Example 7)
1,4-bis(4,5-dihydro-2-oxazolyl instead of 1,3-bis(4,5-dihydro-2-oxazolyl)benzene (1,3-PBO) as chain extender (B) ) Polyamide resin pellets and dumbbell test pieces were produced in the same manner as in Example 2 except that benzene (1,4-PBO) was used.

(Example 8)
1,4-bis(4,5-dihydro-2-oxazolyl instead of 1,3-bis(4,5-dihydro-2-oxazolyl)benzene (1,3-PBO) as chain extender (B) ) Polyamide resin pellets and dumbbell test pieces were produced in the same manner as in Example 5 except that benzene (1,4-PBO) was used.

(Example 9)
Pellets and dumbbell test pieces of a polyamide resin composition were produced in the same manner as in Example 2, except that 1 part by mass of a lubricant (WH255) was further used with respect to 100 parts by mass of the polymer block (A). .

(Comparative example 1)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-7" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Comparative example 2)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-8" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Comparative Example 3)
The procedure was the same as in Example 1, except that the semi-aromatic polyamide "PA-9" was used as the polymer block (A) instead of the semi-aromatic polyamide "PA-1", and the blending amount was changed to that shown in Table 3. Then, pellets and dumbbell test pieces of polyamide resin were produced.

(Comparative Example 4)
Polyamide-based resin pellets and dumbbell test pieces were produced in the same manner as in Example 2, except that the melt-kneading time was changed to 1 minute.

(Comparative Example 5)
Pellets and dumbbell test pieces of polyamide resin were produced in the same manner as in Example 2, except that the blending amount was changed to that shown in Table 3.

(Comparative Example 6)
Pellets and dumbbell test pieces of polyamide resin were produced in the same manner as in Example 2, except that the blending amount was changed to that shown in Table 3.

Various physical property evaluations were performed using the polyamide-based resins and polyamide-based resin compositions obtained in the above Examples and Comparative Examples. Table 3 shows the physical property evaluation results.
Note that the notations in Table 3 are as follows.
"1,3-PBO" indicates "1,3-bis(4,5-dihydro-2-oxazolyl)benzene" manufactured by Tokyo Chemical Industry Co., Ltd.
"1,4-PBO" indicates "1,4-bis(4,5-dihydro-2-oxazolyl)benzene" manufactured by Tokyo Chemical Industry Co., Ltd.
"WH255" indicates "Light Amide WH-255" manufactured by Kyoeisha Chemical Industry Co., Ltd.

(Example 10)
A nucleating agent, an antioxidant and a lubricant were added to the polyamide resin obtained in Example 3 in the amounts shown in Table 4 to obtain a polyamide resin composition. Various physical property evaluations were performed using the obtained polyamide-based resin composition. Table 4 shows the physical property evaluation results.
Note that the notations in Table 4 are as follows.
"ML-112" indicates "Talc ML112" manufactured by Fuji Talc Industry Co., Ltd.
"GA-80" indicates "SUMILIZER GA-80" manufactured by Sumitomo Chemical Co., Ltd.
"Wax-OP" indicates "Licowax OP P" manufactured by Clariant Chemicals.

From the results in Tables 3 and 4, it can be seen that Examples 1 to 10 are excellent in heat resistance, moldability, and fatigue resistance. On the other hand, Comparative Examples 1 to 6 are excellent in heat resistance, but cannot achieve both formability and fatigue resistance.

The polyamide-based resin of this embodiment is obtained by reacting the polymer block (A) and the chain extender (B), and has excellent heat resistance, moldability, and durability such as fatigue resistance. Therefore, the polyamide-based resin and the polyamide-based resin composition of the present embodiment are, for example, electrical and electronic parts, automobile parts, industrial material parts, industrial parts, daily necessities, household goods, sports parts, leisure parts and medical It can be widely used as a material for various parts such as parts. In particular, complex-shaped parts by injection molding, hollow-molded parts by blow molding, hose/tube-shaped parts and films/sheets by extrusion, lightweight parts and insulation materials by injection and/or extrusion foam molding, and additives for resin modification. It is applicable.

Claims (18)

A polyamide-based resin comprising a polymer block (A) containing 50 mol% or more of structural units derived from a polyamide and a chain extender (B),
The content of the polymer block (A) in the polyamide resin is 91.0% by mass or more and less than 99.0% by mass,
A polyamide-based resin having a weight average molecular weight of 40,000 to 150,000. 2. The polyamide-based resin according to claim 1, wherein said polyamide is a semi-aromatic polyamide. 3. The polyamide-based resin according to claim 2, wherein the semi-aromatic polyamide contains diamine units derived from an aliphatic diamine and dicarboxylic acid units derived from an aromatic dicarboxylic acid. 4. The polyamide resin according to claim 2, wherein the semi-aromatic polyamide contains 30 mol % or more of diamine units derived from an aliphatic diamine having 4 to 18 carbon atoms with respect to all diamine units. Claims 2 to 4, wherein the total content of units derived from an aliphatic diamine having 4 to 18 carbon atoms and an aromatic dicarboxylic acid is 40 to 100 mol% with respect to all structural units constituting the semiaromatic polyamide. Polyamide resin according to any one of. The semi-aromatic polyamide is 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,10-decanediamine, 1,11-undecane The polyamide resin according to any one of claims 2 to 5, comprising a diamine unit derived from at least one selected from the group consisting of diamine and 1,12-dodecanediamine. The polyamide-based resin according to claim 6, wherein the semi-aromatic polyamide contains diamine units derived from at least one selected from the group consisting of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. The polyamide-based resin according to any one of claims 1 to 7, wherein the chain extender (B) contains an oxazolyl group. 9. The chain extender (B) according to claim 8, which is 1,3-bis(4,5-dihydro-2-oxazolyl)benzene or 1,4-bis(4,5-dihydro-2-oxazolyl)benzene. of polyamide resin. The polyamide-based resin according to any one of claims 1 to 9, wherein the polymer block (A) has an active terminal functional group content of 75 to 600 µmol/g. The polyamide resin according to any one of claims 1 to 10, wherein the polymer block (A) has a number average molecular weight of 2,000 to 10,000. The polyamide-based resin according to any one of claims 1 to 11, wherein the polymer block (A) has a weight average molecular weight of 8,000 to 50,000. The polyamide-based resin according to any one of claims 1 to 12, wherein the polyamide-based resin has a number average molecular weight of 4,000 to 15,000. The polyamide-based resin according to any one of claims 1 to 13, wherein the polyamide-based resin has a weight average molecular weight of 42,000 to 150,000. A polyamide resin composition comprising the polyamide resin according to any one of claims 1 to 14 and an additive,
A polyamide-based resin composition in which the content of the additive is 0.01 to 100 parts by mass with respect to 100 parts by mass of the polyamide-based resin. 16. The polyamide resin composition according to claim 15, wherein said additive is at least one of a nucleating agent, a reinforcing agent, an antioxidant and a lubricant. The polyamide-based resin composition according to claim 16,
A polyamide-based resin composition, wherein the content of the lubricant is 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyamide-based resin. A molded article made of the polyamide-based resin according to any one of claims 1 to 14 or the polyamide-based resin composition according to any one of claims 15 to 17.