JPH07107127B2 - Polyamide composition - Google Patents

Description

The present invention relates to polyamide compositions, in particular at least 25
The present invention relates to a polyamide composition which is excellent in heat aging resistance at 0 ° C. and is also excellent in heat resistance, mechanical properties and other chemical and physical properties, and is also excellent in moldability.

[Conventional technology]

Conventionally, polytetrafluoroethylene known as Teflon (registered trademark), polyparaphenylene terephthalamide known as Kevlar (registered trademark), Kapton (as engineering plastic excellent in heat resistance, mechanical properties, and chemical-physical properties) Polyimide consisting of a condensate of 4,4′-diaminodiphenyl ether and pyromellitic dianhydride known as (registered trademark), 6,6-
Polyhexamethylene adipamide known as nylon, poly (2,
2,4-trimethylhexamethylene terephthalamide),
Polyphenylene sulfide, polyacetal and the like are used for various purposes.

[Problems to be solved by the invention]

However, when examining the physical properties of each of these, some have poor heat resistance, some have poor mechanical strength, and some have problems such as poor moldability. In terms of aspect, it is not satisfactory either.

Therefore, the applicant of the present application previously proposed, as Japanese Patent Application No. 60-129518, a polyamide composition as a molding material excellent in heat resistance properties, mechanical strength, other chemical and physical properties, and moldability. , Helps to solve the above problems.

The polyamide composition, an aromatic dicarboxylic acid component unit, a polyamide composed of a diamine component unit, and the above polyamide containing a copper compound in the range of 1 to 1000 ppm as copper metal ions, also, In combination with copper metal ions, alkali metal halide ions are contained in the polyamide in an amount of 1 to 10,000 ppm.

However, even with such a polyamide composition, there is room for further improvement. As a result of further tests and studies, the present inventors have found that not only copper compounds and alkali metal halides but also organic stabilizers are used as additives. It has been found that when used together, it can exert a high antioxidant effect and improve various properties such as heat aging resistance at 250 ° C.

[Means for solving problems]

The polyamide composition according to the present invention comprises (A) (a) 60 to 100 mol% of terephthalic acid based on the total amount of dicarboxylic acid component units, and 0 to 40 mol% of aromatic dicarboxylic acid component units other than terephthalic acid. A polyamide comprising a dicarboxylic acid component unit containing up to 10 mol% of a polycarboxylic acid component unit other than the aromatic dicarboxylic acid unit, and (b) an aliphatic diamine component unit, and (B) the above polyamide Copper compound in the range of 1 to 1000 ppm as copper metal ions, and (C) 0.05 to 100 parts by weight of the above polyamide.
An organic stabilizer in an amount of 5 parts by weight and (D) an alkali metal halide in an amount of 1 to 10000 ppm with respect to the polyamide are added.

[Action]

In the polyamide composition according to the present invention, the polyamide (A) comprises (a) 60 to 100 mol% of terephthalic acid and 0 to 40 mol% of an aromatic dicarboxylic acid component other than terephthalic acid, based on the total amount of dicarboxylic acid component units. A dicarboxylic acid component unit containing a unit and, if necessary, up to 10 mol% of a polyvalent carboxylic acid component unit other than the aromatic dicarboxylic acid, and (b) an aliphatic diamine component unit.

The composition of the carboxylic acid component unit (a) is 60 to 100 mol% of terephthalic acid and 0 to 40 mol% of an aromatic dicarboxylic acid component unit other than terephthalic acid based on the total amount of the dicarboxylic acid component unit. Depending on the polycarboxylic acid component unit other than aromatic dicarboxylic acid up to 10 mol%,
Specific examples of the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit include component units such as isophthalic acid, phthalic acid, 2-methylterephthalic acid, and naphthalenedicarboxylic acid. Among these, an isophthalic acid component unit or a naphthalenedicarboxylic acid component unit, particularly an isophthalic acid component unit is preferably used.

Of the dicarboxylic acid component units (a), terephthalic acid is 60
When it is less than mol%, the molded product obtained from the composition containing such a polyamide has mechanical properties such as heat aging resistance at 250 ° C. and heat resistance including heat deformation temperature, tensile strength, bending strength, wear resistance and the like. There is also a disadvantage in terms of chemical and physical properties such as chemical resistance and water resistance.

Further, as the polyvalent carboxylic acid component unit other than the aromatic dicarboxylic acid that can be blended up to 10 mol% if necessary, for example, adipic acid, an aliphatic dicarboxylic acid such as sebacic acid, and trimellitic acid Examples thereof include trivalent or higher polyvalent aromatic carboxylic acids such as pyromellitic acid.

In the polyamide composition according to the present invention, the aliphatic diamine component unit is a linear or branched alkylenediamine component unit having 4 to 25 carbon atoms, particularly 6 to 18 carbon atoms. As a specific example of such an alkylenediamine component unit, for example, 1,
4-diamino-1,1-dimethylbutane, 1,4-diamino-
1-ethylbutane, 1,4-diamino-1,2-dimethylbutane, 1,4-diamino-1,3-dimethylbutane, 1,4-diamino-1,4-dimethylbutane, 1,4-diamino-2 , 3-dimethylbutane, 1,2-diamino-1-butylethane, 1,6
-Diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,6-diamino-2,5-dimethylhexane, 1,6-diamino-2,4-dimethylhexane, 1,6-diamino- 3,3-dimethylhexane, 1,6-diamino-2,2
-Dimethylhexane, 1,9-diaminononane, 1,6-diamino-2,2,4-trimethylhexane, 1,6-diamino-2,
4,4-trimethylhexane, 1,7-diamino-2,3-disimethylheptane, 1,7-diamino-2,4-dimethylheptane, 1,7-diamino-2,5-dimethylheptane, 1,7 -Diamino-2,2-dimethylheptane, 1,10-diaminodecane, 1,8-diamino-1,3-dimethyloctane, 1,8-diamino-1,4-dimethyloctane, 1,8-diamino-2 ,Four
-Dimethyloctane, 1,8-diamino-3,4 dimethyloctane, 1,8-diamino-4,5-dimethyloctane, 1,8-
Diamino-2,2-dimethyloctane, 1,8-diamino-3,
3-dimethyloctane, 1,8-diamino-4,4-dimethyloctane, 1,6-diamino-2,4-diethylhexane, 1,
Component units such as 9-diamino-5-methylnonane and 1,11-diaminoundecane 1,12-diaminododecane can be exemplified.

Of these, 1,6-diaminohexane, 1,8-
Component units such as diaminooctane, 1,10-diaminodecane, and 1,12-diaminododecane, or mixed component units thereof are preferably used.

In the polyamide composition according to the present invention, the composition of the above-mentioned dicarboxylic acid component unit (a) is preferably selected according to the carbon number of the diamine. Thus, when the composition of the dicarboxylic acid component unit (a) is selected according to the number of carbon atoms of the diamine, in particular, the obtained polyamide composition has excellent moldability, heat aging resistance at 250 ° C. and thermal deformation. This is because it gives a molded article having excellent heat resistance characteristics such as temperature and mechanical characteristics such as bending strength and abrasion resistance.

When the aliphatic alkylenediamine is used as the diamine component (b) in the (A) polyamide of the present invention, when the aliphatic alkylenediamine has 6 carbon atoms, the dicarboxylic acid component unit (a) is used. The composition is preferably in the range of 60 to 85 mol% of the terephthalic acid component unit and in the range of 15 to 40 mol% of the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit. When the number of carbon atoms of the aliphatic alkylenediamine is 8, for example, the composition of the dicarboxylic acid component unit (a) is preferably such that the terephthalic acid component unit is in the range of 65 to 100 mol%, and aromatics other than the terephthalic acid component unit. Dicarboxylic acid component unit is 0-35
It is in the range of mol%. When the aliphatic alkylenediamine component unit (b) has, for example, 10 to 18 carbon atoms,
The composition of the dicarboxylic acid component unit (a) is preferably such that the terephthalic acid component unit is in the range of 75 to 100 mol%, and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is 0.
In the range of up to 25 mol%.

Further, in the polyamide composition according to the present invention, the above-mentioned polyamide is soluble in concentrated sulfuric acid at a temperature of 50 ° C., and the intrinsic viscosity [η] measured in concentrated sulfuric acid at a temperature of 30 ° C. is 0.5 dl / It is preferably at least g. Preferably, [η] is 0.6 dl / g or more, particularly preferably 0.7 to 3.0 d.
It is in the l / g range.

Such concentrated sulfuric acid-soluble polyamide can be obtained by a method already known in the art. For example, Po
lymer Reviews, 10 , Condensation Polymers by Interfac
ial and Solution Methods (PWMorgan, Interscien
ce Publishers (1965)) and Makromol.Chem., 47 , 93-11
3 (1961)), it can be obtained by polycondensing the diacid component halide of the dicarboxylic acid which is the above-mentioned polyamide constituent unit and the diamine by the solution method. It can also be obtained by an interfacial polymerization method. Alternatively, it can be obtained by polycondensation of the dicarboxylic acid component and the diamine or its nylon salt by a melting method in the presence or absence of a solvent such as water. Further, it can also be obtained by polycondensing the polyamide oligomer obtained by the former method by a solid phase polymerization method.

Further, in the polyamide composition according to the present invention, the polyamide has not only the above concentrated sulfuric acid-soluble polyamide but also a composition in the same range as this concentrated sulfuric acid-soluble polyamide, but contains a polyamide insoluble in concentrated sulfuric acid at 50 ° C. May be. Here, the polyamide insoluble in concentrated sulfuric acid at 50 ° C. means that the polyamide is crushed and a concentrated 1% by weight concentrated sulfuric acid solution of polyamide passing through 32 mesh is heated and stirred at 50 ° C. for 10 hours, and then the temperature is raised to 50 ° C. A polyamide obtained by filtering soluble parts by filtering with a 2G glass filter. Such concentrated sulfuric acid insoluble polyamide is not particularly limited, but has a melt viscosity (MFR) at 360 ° C. and a load of 2.16 kg,
It is usually 20 g / 10 minutes or less, preferably 5 g / 10 minutes or less, and particularly preferably 0.1 g / 10 minutes or less.

Such concentrated sulfuric acid-insoluble polyamide can be produced as a by-product during the production of the concentrated sulfuric acid-soluble polyamide. Moreover, the production amount can be intentionally increased by selecting the reaction conditions. Therefore, in such a case, a mixture of concentrated sulfuric acid-soluble polyamide and concentrated sulfuric acid-insoluble polyamide can be obtained. Further, if necessary, the concentrated sulfuric acid-soluble polyamide or the mixture of the concentrated sulfuric acid-soluble polyamide and the concentrated sulfuric acid-insoluble polyamide may be further crosslinked to have a high molecular weight so that the concentrated sulfuric acid is insoluble.

Therefore, without any limitation, as a method for producing a concentrated sulfuric acid-insoluble polyamide or a mixture of concentrated sulfuric acid-soluble polyamide and concentrated sulfuric acid-insoluble polyamide, for example,
A method for further solid-phase polymerization of the concentrated sulfuric acid-soluble polyamide,
When producing concentrated sulfuric acid-soluble polyamide by melt polycondensation, the polycondensation temperature is set higher, for example, about 340 ° C finally.
The above method, the charge molar ratio of the diamine and dicarboxylic acid components as 1.03 or more, a method of polycondensing these,
Examples thereof include a method in which a polyamine or polycarboxylic acid having a functionality of 3 or more is used together with a diamine and a dicarboxylic acid component, and polycondensation thereof is performed.

In the production of the concentrated sulfuric acid-soluble polyamide or the concentrated sulfuric acid-insoluble polyamide, a catalyst or stabilizer such as phosphoric acid, hypophosphite, octyl phosphate, tristridecyl phosphite may be used.

In the polyamide composition according to the present invention, the concentrated sulfuric acid-insoluble polyamide is preferably contained in an amount of 1000 parts by weight or less based on 100 parts by weight of concentrated sulfuric acid-soluble polyamide. In particular, according to the present invention, with respect to 100 parts by weight of concentrated sulfuric acid-soluble polyamide, concentrated sulfuric acid-soluble polyamide 2-1
When it is contained in an amount of 000 parts by weight, preferably 3 to 600 parts by weight, particularly preferably 5 to 400 parts by weight, a molded product obtained from such a polyamide composition has excellent mechanical strength such as bending strength.

Here, the ratio of concentrated sulfuric acid-soluble polyamide and concentrated sulfuric acid-insoluble polyamide in polyamide is calculated by the following method. That is, a 1% by weight concentrated sulfuric acid solution of a polyamide mixture crushed to pass through 32 mesh was stirred at a temperature of 50 ° C.
After heating for 10 hours and cooling to room temperature, the mixture is filtered with a 2G glass filter, and the polyamide obtained as a precipitate and the polyamide obtained by precipitating the polyamide contained in the filtrate with water are dried, Weigh each one.

The polyamide composition according to the present invention contains a copper compound. As such a copper compound, copper halide and copper phosphate are particularly preferable. As the copper halide, for example,
Cuprous chloride, cuprous bromide, cuprous iodide, cupric chloride,
Examples of cupric bromide and the like include cupric phosphate, cupric pyrophosphate, and the like. Also,
Organic copper compounds such as copper acetate, copper salicylate, and copper benzoate, and copper oxide, copper sulfide, copper nitrate, copper sulfate, and copper sulfamate can also be used. These copper compounds, in the polyamide composition according to the present invention, as the copper metal ion relative to the polyamide is 1 to 1000 ppm, preferably 1
It is compounded in the range of 0 to 100 ppm. When the compounding amount of the copper compound is less than 1 ppm as copper metal ions with respect to the polyamide, the improvement of the heat aging resistance at 250 ° C. high temperature of the molded article obtained from the polyamide composition is not yet sufficient, while, When a large amount of copper metal ions exceeding 1000 ppm is compounded, the mechanical strength such as tensile strength and bending strength will decrease.

When the copper compound and the organic stabilizer are used in combination with the polyamide, the molded product obtained from the polyamide is significantly excellent in antioxidant property.

Examples of the organic stabilizer include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N'-bis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2'-oxazamide bis-ethyl (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tris [β- (3,5 -Ge-t
-Butyl-4-hydroxyphenyl) propionyl-oxyethyl] isocyanurate and other phenolic stabilizers, N, N'-diphenyl-p-phenylenediamine, 2,
2,4-trimethyl-1,2-dihydroquinoline polymer, p,
p'-dioctyldiphenylamine, N-phenyl-
N '-(3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine, 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, N,
Amine stabilizers such as N'-di-β-naphthyl-p-phenylenediamine and phenyl-α-naphthylamine, distearyl disulfide, distearyl thiodipropionate, 2-mercaptobenzimidazole, pentaerythrityl-tetra (β Thioether stabilizers such as -mercaptolauryl) propionate, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-t-butylphenyl) Pentaerythritol-di-phosphite, Tris (2,4-di-t-butylphenyl) phosphite, Tetrakis (2,4-di-t-butylphenyl)
Phosphorus stabilizers such as -4,4'-biphenylene phosphonite, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, bis (2,2,6, Other stabilizers such as 6-tetramethyl-4-piperidyl) sebacate can be exemplified. Among these, among others, p, p'-dioctyldiphenylamine, 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, N,
N'-di-β-naphthyl-p-phenylenediamine, phenyl-α-naphthylamine, tris (2,4-di-t-
Butylphenyl) phosphite, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate It is suitable.

These organic stabilizers are added in an amount of 0.05 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the above polyamide.

When the compounding amount is less than 0.05 part by weight, the effect of improving the heat resistance stability at a high temperature of 250 ° C is insufficient. On the other hand, when the compounding amount exceeds 5 parts by weight, bleedout or mechanical strength is caused. Will decrease.

In the polyamide composition of the present invention, an alkali metal halide is added in addition to the copper compound and the organic stabilizer.

Examples of the alkali metal halide include lithium chloride, lithium bromide, lithium iodide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, potassium bromide, potassium iodide and the like. Among them, potassium iodide is particularly preferable because it has excellent effects.

The amount of alkali metal halide compounded is 1 to 10000 ppm, preferably 10 to 5000 ppm of metal ion relative to polyamide.
It is mixed in the range of. As in the case of the copper compound, when the content of the alkali metal halide ion is less than 1 ppm with respect to the polyamide, the effect of improving the heat aging resistance at 250 ° C. of the molded product by the addition of the alkali metal halide is still low. On the other hand, when it is mixed in a large amount exceeding 10,000 ppm, the mechanical strength at room temperature, such as tensile strength and bending strength, decreases. Further, in the present invention, a copper composition, an organic stabilizer and an alkali metal halide compound may be added to the raw materials and polycondensation may be carried out to obtain a polyamide composition.

In the polyamide composition according to the present invention, in addition to the above-mentioned copper compound, organic stabilizer, and alkali metal halide, conventionally known polymers, plasticizers, release agents, lubricants, and fillers as necessary. Etc. may be contained. As the above polymer, nylon 66, nylon 6, nylon 46
Examples thereof include polyamides and the like.

As the filler, conventionally known powder, plate,
Organic or inorganic substances having various forms such as fibrous or cloth can be used.

As the inorganic filler, for example, silica, alumina, silica alumina, talc, diatomaceous earth, clay, kaolin, quartz, glass, mica, graphite, molybdenum disulfide, gypsum, red iron oxide, titanium dioxide, zinc oxide, aluminum, Powdery or plate-like materials such as copper and stainless steel,
Glass fiber, carbon fiber, boron fiber, ceramic fiber,
Examples thereof include fibrous materials such as asbestos fibers and stainless steel fibers, or cloth-shaped materials as secondary processed products thereof.

As the organic filler, for example, polybalaphenylene terephthalamide, polymetaphenylene terephthalamide, polyparaphenylene isophthalamide, polymetaphenylene isophthalamide, a condensate of diaminodiphenyl ether and terephthalic acid and / or isophthalic acid, A wholly aromatic polyamide of a condensate of para or metaaminobenzoic acid, a wholly aromatic polyamideimide such as a condensate of diaminodiphenyl ether and trimellitic anhydride and / or pyromellitic acid, a wholly aromatic polyimide, polybenzimidazole Examples thereof include a heterocycle-containing polymer such as polyimidazophenanthroline, a powdery material such as polytetrafluoroethylene, a plate-like material, a fibrous material, or a cloth-like material as a secondary processed product thereof. The above-mentioned fillers are blended alone or as a mixture, and if necessary, these fillers may be treated with a silane coupling agent, a titanium coupling agent, or the like.

Among the above-mentioned fillers, silica, silica-alumina, alumina, titanium dioxide, graphite, molybdenum dioxide, polytetrafluoroethylene and the like are preferably used as the powdery material, but especially graphite, molybdenum dioxide and polytetrafluoroethylene. Is the coefficient of dynamic friction, Taber wear, and limit of the molded product obtained from the composition.
It is preferably used because it improves abrasion resistance such as PV value. Such a filler is preferable when the average particle diameter is usually in the range of 0.1 mμ to 200 μ, particularly in the range of 1 mμ to 100 μ, because the abrasion resistance of the obtained molded product is remarkably improved.

The amount of the powdery filler as described above is the polyamide composition.
With respect to 100 parts by weight, 200 parts by weight or less, preferably 100 parts by weight or less, particularly preferably 0.5 to 50 parts by weight.

Further, when the fiber made of the wholly aromatic polyamide is used as the filler, the molded product obtained from the composition has further improved mechanical properties such as tensile strength and Izod impact strength, and heat resistance properties such as heat distortion temperature. When glass fiber, carbon fiber or boron fiber is used as the fibrous inorganic filler, mechanical properties such as tensile strength, bending strength and bending elastic modulus of the molded product obtained from the composition, heat deformation temperature, etc. The heat resistance and chemical / physical properties such as water resistance are further improved.

These fibrous fillers are usually 0.1 to 20 mm, especially 1 to 1
It is preferable to have an average length in the range of 0 mm. The blending amount is usually 200 parts by weight or less, preferably 5 to 180 parts by weight, and particularly preferably 5 to 150 parts by weight with respect to 100 parts by weight of polyamide.

The polyamide composition according to the present invention can be molded by a usual melt molding such as compression molding, injection molding or extrusion molding.

〔The invention's effect〕

As described above, the polyamide composition according to the present invention is excellent in an antioxidant effect by adding a copper compound, an organic stabilizer and an alkali metal halide together to a polyamide having a predetermined composition, and is at least 250 ° C. The heat aging resistance at high temperature is remarkably improved. Of course, heat resistance characteristics such as melting point, glass transition point and heat distortion temperature, tensile strength, bending strength, impact characteristics, mechanical characteristics such as dynamic friction coefficient, Taber friction, chemical resistance, boiling water resistance, saturation water absorption, etc. Physical properties, fluidity of melted composition, melt compression moldability, melt injection moldability, melt extrusion moldability, and other molding properties.

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.
In the table below, the abbreviations represent the following compounds, respectively.

<Phenolic stabilizer> A: Pentaerythrityl-tetrakis [3- (3,5-di-
t-Butyl-4-hydroxyphenyl) propionate] B: N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine C: 2,2'-ogizamide bis- Ethyl (3,5-di-t-butyl-4-hydroxyphenyl) propionate D: tris [β- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl-oxyethyl] isocyanurate <amine stable Agent> E: N, N'-diphenyl-p-phenylenediamine F: 2,2,4-trimethyl-1,2-dihydroquinoline polymer G: p, p'-dioctyldiphenylamine H: N-phenyl-N ' -(3-methacryloyloxy-
2-hydroxypropyl) -p′-phenylenediamine I: 4,4′-bis (α, α-dimethylbenzyl) diphenylamine J: N, N′-di-β-naphthyl-p-phenylenediamine K: phenyl-α -Naphthylamine <thioether stabilizer> L: Distearyl disulfide M: Distearyl thiodipropionate N: 2-Mercaptobenzimidazole O: Pentaerythrityl-tetra (β-mercaptolauryl) propionate <Phosphorus stabilizer> P: Bis (2,6-di-t-butyl-4-methylphenyl)
Pentaerythritol-di-phosphite Q: Bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite R: Tris (2,4-di-t-butylphenyl) phosphite S: Tetrakis ( 2,4-di-t-butylphenyl) -4,4 '
-Biphenylene phosphonite <Other organic stabilizers> T: 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole U: Bis (2,2,6,6 -Tetramethyl-4-piperidyl) sebacate <Copper compound> CuI: Cuprous iodide <Alkali metal halide> KI: Potassium iodide <Examples 1 to 21 and Comparative examples 1 to 8> 70 mol of terephthalic acid, isophthalic acid Polyamide consisting of 30 moles of acid and 100 moles of hexamethylenediamine is crushed with a crusher (passes through 32 mesh) and dried under conditions of 100 ° C and 1 mmHg for 12 hours, and a predetermined amount of copper compound, organic stabilizer and halogen. The alkali metal chloride was dry blended in nitrogen and then granulated by an extruder. The obtained pellets were crushed with a crusher and made into powder.

At the same time, the above-mentioned polyamide containing no stabilizer at all, one containing only a copper compound, and one containing only an organic stabilizer were prepared to obtain the same ground powder.

The oxygen absorption amount was measured when each of these powders was left in an oxygen atmosphere at 250 ° C. for 30 minutes to 180 minutes by the oxygen absorption method, and the antioxidant effect was evaluated.

As shown in Table 1, the results show that the polyamide compounded with the copper compound, the organic stabilizer and the alkali metal halide has the smallest oxygen absorption amount and is excellent in the antioxidant effect.

<Examples 22 to 25 and Comparative Example 9> Test pieces were obtained by press molding using the polyamide composition powders of Examples 9, 15, 19, 21 and Comparative Example 1 at 150 ° C and 180 ° C.
Bending strength was measured by oven aging under the condition of ° C. The results are shown in Table 2.

Claims (1)

[Claims] 1. A) (a) 60 to 100 mol% of terephthalic acid based on the total amount of dicarboxylic acid component units, 0 to 40 mol% of aromatic dicarboxylic acid component units other than terephthalic acid, and, if necessary, To a polyamide composed of a dicarboxylic acid component unit containing up to 10 mol% of a polyvalent carboxylic acid component unit other than the aromatic dicarboxylic acid, and (b) an aliphatic diamine component unit; Copper metal ion content is in the range of 1 to 1000 ppm, and (C) the organic stabilizer is added in a proportion of 0.05 to 5 parts by weight with respect to 100 parts by weight of the polyamide, and (D) ) A polyamide composition, wherein an alkali metal halide is added to the above polyamide in an amount of 1 to 10,000 ppm.