JPH0615665B2 - Polyamide composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polyamide composition, and more particularly, it has excellent heat aging resistance, heat resistance, mechanical properties, and chemical / physical properties. The present invention relates to a polyamide composition having excellent moldability as well as giving a molded article having excellent moldability.

(Prior Art) In general, thermoplastic resins such as polyolefin, polyester, and polyamide have excellent moldability, so compression molding,
Although melt molding such as injection molding or extrusion molding can be easily performed, the engineering plastics are still unsatisfactory in any of the heat resistance, mechanical properties and chemical properties, so It is used in each general-purpose molding field by taking advantage of the characteristics of.

On the other hand, as an engineering plastic that has better heat resistance, mechanical properties, and chemical and physical properties than before,
Polytetrafluoroethylene known as Teflon®, polyparaphenylene terephthalamide known as Kevlar®, 4,4′-diaminodiphenyl ether and pyromellitic anhydride known as Kapton® Polyimide composed of a condensation product with poly (6,6-nylon), polyhexamethylene adipamide known as 6,6-nylon, poly (2,2,4-trimethylhexamethylene terephthalamide) known as Trogamide T (registered trademark), polyphenylene Ruffid, polyacetal and the like are used for various purposes.

However, of these, polytetrafluoroethylene,
Although polyparaphenylene terephthalamide and the above-mentioned polyimide have excellent heat resistance, mechanical properties, and chemical-physical properties, they cannot be melt-molded, so that their fields of use are extremely limited. Against these,
Polyphenylene sulfide, polyhexamethylene adipamide, 2,2,4-trimethylhexamethylene terephthalamide, polyacetal, etc. all have the advantage of being melt-molded, but on the other hand, polyphenylene sulfide Is inferior in heat resistance properties such as melting point, glass transition point, heat distortion temperature and mechanical properties such as impact strength and abrasion resistance, while polyhexamethylene adipamide, 2,4,4-trimethylhexamethylene terephthalamide, etc. Polyamides are all glass transition points, heat resistance characteristics such as heat distortion temperature, tensile strength,
It is inferior in mechanical properties such as bending strength, limit PV value, abrasion resistance, and chemical properties such as chemical resistance, boiling water resistance and saturated water absorption.
Further, polyacetal is inferior in melting point, heat distortion temperature and the like, heat resistance characteristics and mechanical strength such as bending strength, impact strength and abrasion resistance.

In order to solve the problems in the conventional engineering plastics as described above, the present inventors have already
Polyamide consisting of an aromatic dicarboxylic acid component unit and an aliphatic alkylenediamine component unit having a terephthalic acid component unit as a main component is excellent in heat resistance properties, mechanical strength, chemical-physical properties and molding properties, in particular, We have found that it has excellent sliding characteristics (Japanese Patent Application No. 59-120).
No. 40). However, as a result of further intensive studies on the polyamide to improve its heat aging resistance, the present inventors have found that addition of a predetermined alkyl-substituted phenol compound gives a molded article having excellent heat aging resistance. The present invention has been completed by finding that a polyamide composition as a molding material can be obtained.

(Structure of the Invention) The first polyamide composition according to the present invention comprises (A) (a) a terephthalic acid component unit of 60 to 100 mol%.
And an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit in the range of 0 to 40 mol%, and (b) an aliphatic alkylenediamine having 6 to 18 carbon atoms. A polyamide composed of component units, and (B) a general formula (I) in the range of 0.1 to 5% by weight based on the above polyamide. (However, X represents an ester bond, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent an alkylene group having 1 to 10 carbon atoms.) It is characterized by containing.

The second polyamide composition according to the present invention comprises (A) (a) a terephthalic acid component unit of 60 to 100 mol%.
And an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit in the range of 0 to 40 mol%, and (b) an aliphatic alkylenediamine having 6 to 18 carbon atoms. A polyamide composed of component units, and (B) a general formula (II) in the range of 0.1 to 5% by weight based on the above polyamide. (However, X ¹ represents an ester bond, X ² represents an ether bond, R ¹ and R ² each independently represent an alkyl group, R ³
And R ⁴ represent an alkylene group having 1 to 10 carbon atoms. ) It is characterized by containing an alkyl-substituted phenol compound represented by

In the polyamide composition according to the present invention, the polyamide (A) has (a) a terephthalic acid component unit in the range of 60 to 100 mol% and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit of 0 to 40. It consists of aromatic dicarboxylic acid component units in the range of mol% and (b) aliphatic alkylenediamine component units having 6 to 18 carbon atoms.

The composition of the aromatic dicarboxylic acid component unit (a) may be a terephthalic acid component unit alone, but is a mixture of a terephthalic acid component unit and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit. You can buy it. 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.

In the present invention, the aromatic dicarboxylic acid component unit
Of (a), terephthalic acid accounts for 60 to 100 mol%, and aromatic dicarboxylic acid other than the terephthalic acid component unit is required to be in the range of 0 to 40 mol%. Of the aromatic dicarboxylic acid component units (a), when the terephthalic acid content is less than 60 mol% and the aromatic dicarboxylic acid component units other than the terephthalic acid component units are more than 40 mol%, the polyamide is included. Molded product obtained from the composition is heat resistance including heat aging resistance and heat distortion temperature, tensile strength,
Inferior in mechanical properties such as bending strength and abrasion resistance, and chemical and physical properties such as chemical resistance and water resistance.

However, in the present invention, the aromatic dicarboxylic acid component unit (a) is a terephthalic acid component unit and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit,
There is no problem in containing a small amount of a polyvalent carboxylic acid component unit such as adipic acid, sebacic acid, trimellitic acid, and pyromellitic acid.

In the polyamide composition according to the present invention, the aliphatic alkylenediamine component unit (b) is a linear or branched alkylenediamine component unit having 6 to 18 carbon atoms. Specific examples of the 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-dimethylheptane, 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, -diamino-1,4-dimethyloctane, 1,8-diamino-
2,4-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, 1,9-diamino-5-methylnonane, 1,11-diamino Undecane, 1,12
Examples thereof include component units such as diaminododecane.

Among these, especially 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 aromatic dicarboxylic acid component unit (a) described above is preferably selected according to the carbon number of the aliphatic alkylenediamine. Thus, depending on the carbon number of the aliphatic alkylenediamine, when selecting the composition of the aromatic dicarboxylic acid component unit (a), in particular, the resulting polyamide composition is excellent in moldability, heat aging resistance and This is because a molded product having excellent heat resistance such as heat distortion temperature and mechanical properties such as bending strength and wear resistance is provided.

That is, when the number of carbon atoms of the aliphatic alkylenediamine is 6, for example, the composition of the aromatic dicarboxylic acid component unit (a) is preferably 60 to 80 terephthalic acid component units.
Mol% and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is in the range of 20 to 40 mol%. When the number of carbon atoms of the aliphatic alkylenediamine is 8, for example, the composition of the aromatic dicarboxylic acid component unit (a) is preferably in the range of 65 to 100 mol% of terephthalic acid component unit, and other than the terephthalic acid component unit. The aromatic dicarboxylic acid component unit of is in the range of 0 to 35 mol%. When the aliphatic alkylenediamine component unit (b) has 10 to 18 carbon atoms, the composition of the aromatic dicarboxylic acid component unit (a) is preferably 75 to 100 mol% of the terephthalic acid component unit. And the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is in the range of 0 to 25 mol%.

In the polyamide composition according to the present invention, the polyamide is soluble in concentrated sulfuric acid at a temperature of 50 ° C. and has an intrinsic viscosity [η] of 0.5 dl measured in concentrated sulfuric acid at a temperature of 30 ° C. / g or more is preferable. [Η] is preferably 0.6 dl / g or more, particularly preferably 0.
It is in the range of 7 to 3.0 dl / g.

Such concentrated sulfuric acid-soluble polyamide can be obtained by a method already known in the art. For example, P
olymer Reviews, 10 , Condensation Polymers by Inter
facial and Solution Methods (P.W.Morgan, Inte
rscience Publishers (1965)) and Makromol. Chem., 4
7 , 93-113 (1961)), the polycondensation of a diacid halide of an aromatic dicarboxylic acid, which is the above-mentioned polyamide constituent unit, and an aliphatic alkylenediamine by a solution method. You can get it. Also,
It can also be obtained by an interfacial polymerization method. Alternatively, it can be obtained by polycondensing the aromatic dicarboxylic acid and alkyne diamine or a nylon salt thereof in the presence or absence of a solvent such as water by a melting method. . 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 concentrated sulfuric acid-soluble polyamide described above 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. And a soluble portion is removed by filtration with a 2 G glass filter. Such concentrated sulfuric acid-insoluble polyamide is not particularly limited, but its melt viscosity (MFR) at 360 ° C. and a load of 2.16 kg is usually 20 g / 10 minutes or less, preferably 5 g / 10 minutes or less, Particularly preferably,
It is 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. In addition, 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, as a method for producing a concentrated sulfuric acid-insoluble polyamide or a mixture of concentrated sulfuric acid-soluble polyamide and concentrated-flow acid-insoluble polyamide, for example, without any limitation, for example,
A method for further solid-phase polymerization of the concentrated sulfuric acid-soluble polyamide,
In producing concentrated sulfuric acid-soluble polyamide by melt polycondensation, the polycondensation temperature is higher, for example, about 340 finally.
C. or higher, a method of polycondensing alkylenediamine and aromatic dicarboxylic acid at a charged molar ratio of 1.03 or higher, alkylenediamine and aromatic dicarboxylic acid, and bifunctional or higher polyamine or polycarboxylic acid And a method of polycondensing the same can be exemplified.

When producing the concentrated sulfuric acid-soluble polyamide or the concentrated sulfuric acid-insoluble polyamide, a catalyst or stabilizer such as phosphoric acid, hypophosphite, octyl phosphate, or 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 the concentrated acid-soluble polyamide. In particular, according to the present invention, the concentrated sulfuric acid-insoluble polyamide is contained in an amount of 2 to 1000 parts by weight, preferably 3 to 600 parts by weight, particularly preferably 5 to 400 parts by weight, based on 100 parts by weight of concentrated sulfuric acid-soluble polyamide. The molded product obtained from such a polyamide composition has excellent mechanical strength such as bending strength.

Here, the ratio of the concentrated sulfuric acid-soluble polyamide and the concentrated sulfuric acid-insoluble polyamide in the polyamide is determined by the following method. That is, a 1% by weight concentrated sulfuric acid solution of a polyamide mixture pulverized into 32 mesh passes was heated with stirring at a temperature of 50 ° C. for 10 hours, cooled to room temperature, and then filtered through a 2G glass filter to obtain a polyamide obtained as a precipitate. And the polyamide obtained by precipitating the polyamide contained in the filtrate with water are collected, dried, and the respective weights are measured.

The first polyamide composition according to the present invention contains an alkyl-substituted phenol compound represented by the general formula (I).

Therefore, in the present invention, it is known as Irganox 259 (manufactured by Ciba Geigy). (However, all of t-Bu represent a t-butyl group.) And the like can be preferably used as the alkyl-substituted phenol compound.

The second polyamide composition according to the present invention contains an alkyl-substituted phenol compound represented by the general formula (II).

Therefore, in the present invention, it is known as Dolphin Knox 245 (manufactured by Ciba Geigy). (However, t-Bu represents a t-butyl group.) And the like can be preferably used as the alkyl-substituted phenol compound.

Such an alkyl-substituted phenol compound is compounded in the polyamide composition according to the present invention in an amount of 0.1 to 5% by weight based on the polyamide. When the compounding amount of the alkyl-substituted phenol compound is less than 0.1% by weight with respect to the polyamide, the heat aging resistance of the molded product obtained from such a polyamide composition is not sufficiently improved, while 5% by weight is obtained. %, The mechanical strength such as tensile strength and bending strength will decrease.

Further, in the present invention, the alkyl-substituted phenol compound may be added to a polyamide raw material and polycondensation may be performed to obtain a polyamide composition.

Furthermore, in the polyamide composition according to the present invention, in addition to the above-mentioned alkyl-substituted phenol compound, if necessary, a conventionally known polymer, stabilizer, plasticizer,
Release agents, lubricants, fillers and the like may be contained. Examples of the polymer include nylon 66 and nylon 6 polyamide.

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.

Examples of the organic filler include polyparaphenylene terephthalamide, polymetaphenylene terephthalamide, polyparaphenylene isophthalamide, polymetaphenylene isophthalamide, diaminodiphenyl ether and terephthalic acid and / or isophthalic acid. Condensates with acids, wholly aromatic polyamides such as condensates of para- or meta-aminobenzoic acid, wholly aromatic polyamideimides such as condensates of diaminodiphenyl ether and trimellitic anhydride and / or pyromellitic acid, wholly aromatic Heterocyclic ring-containing polymers such as group-type polyamides, polybenzimidazoles, polyimidazophenanthrolines, powders such as polytetrafluoroethylene, plates, fibrous substances, or cross-shaped substances as secondary processed products thereof. Can be mentioned.

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, as the powdery material, silica, silica alumina, alumina, titanium dioxide, graphite, molybdenum dichloride, polytetrafluoroethylene, etc. are preferably used, but in particular, graphite, molybdenum dichloride and Polytetrafluoroethylene is preferably used because it improves wear resistance such as dynamic friction coefficient, Taber wear, and limit PV value of the molded product obtained from the composition.
Such fillers typically have an average particle size of 0.1 mμ to 2
A range of 00 μ, particularly a range of 1 mμ to 100 μ is preferable because the abrasion resistance of the obtained molded product is remarkably improved.

The amount of the powdery filler as described above is 200 parts by weight or less, preferably 100 parts by weight of the polyamide composition,
The amount is 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 mechanical properties such as tensile strength and Izod impact strength of the molded product obtained from the composition, and the heat resistance properties such as heat distortion temperature are further improved. 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
It preferably has an average length in the range of 1-10 mm. The blending amount is usually about 100 parts by weight of polyamide,
It is 200 parts by weight or less, preferably 5 to 180 parts by weight, particularly preferably 5 to 150 parts by weight.

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

(Effect of the invention) As described above, the polyamide composition of the present invention contains a polyamide having a predetermined composition and a predetermined alkyl-substituted phenol compound, and a molded article obtained from such a polyamide composition is Its heat aging resistance is remarkably improved. Heat resistance such as theory, melting point, glass transition point and heat deformation temperature, tensile strength, bending strength, impact characteristics, dynamic friction coefficient, mechanical characteristics such as Taber abrasion, chemical resistance, boiling water resistance, saturated water absorption rate, etc. It is also excellent in molding properties such as chemical and physical properties, flowability of melt composition, melt compression moldability, melt injection moldability and melt extrusion moldability.

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

TA: terephthalic acid IA: isophthalic acid C ₆ DA: 1,6-hexamethylenediamine C ₁₀ DA: 1,10-decamethylenediamine The method for preparing test pieces and the evaluation method for each performance are as follows.

(Preparation of polyamide composition, test piece and evaluation of physical properties) Polyamide was crushed by a crusher (passed through 32 mesh) and dried for 12 hours at 100 ° C and 1 mmHg,
A predetermined amount of a phenol compound was dry blended in nitrogen to obtain a polyamide composition.

Then, such a polyamide composition was hot-pressed with a press molding machine in a nitrogen atmosphere under a pressure of 100 kg / cm ^{2 at} a temperature 20 ° C. higher than the melting point of the polyamide.
Cold pressing was performed at a temperature of 20 ° C. to prepare a compression molded plate having a thickness of 2 to 4 mm. Each of these molded plates was cut into test pieces having the dimensions shown in Table 1, then left in an atmosphere having a temperature of 23 ° C. and a relative humidity of 65% for 96 hours, and then subjected to each test. The heat aging resistance was evaluated by the bending strength after holding the bending test piece in an air oven at 250 ° C. for 2 days and the holding ratio with respect to the initial value.

In addition, the glass fiber compounded molded product was 60 parts by weight of crushed and dried polyamide, 40 parts by weight of glass fiber (average length 6 mm, manufactured by Nitto Boseki Co., Ltd., CS 6PE-231) and a predetermined stability. Single screw extruder (L / D = 28, 2
0 mm diameter) and mixed to obtain a polyamide composition in the form of a strand having a size of about 6 mm. Using this, press molding was carried out in the same manner as in the case where the above glass fiber was not compounded to prepare a test piece.

Reference Example 1 123.6 g (0.744 mol) of terephthalic acid, 52.9 g (0.318 mol) of isophthalic acid, 123.4 g (1.06 mol) of hexamethylenediamine and 33 g of ion-exchanged water were charged into a 1-volume autoclave, After sufficiently substituting with nitrogen, the temperature was raised to 280 ° C. over 2 hours with stirring. Further, the reaction was allowed to proceed at 280 ° C. for 1 hour in the sealed state, stirring was stopped, and the reaction mixture was taken out from the bottom of the autoclave at a differential pressure of 10 kg / cm ² . This was dried in nitrogen at 100 ° C. and 100 mmHg overnight.

Use this oligomer for twin-screw extruder (Screen diameter 30 mm, L
/ D = 42, barrel temperature (° C) 30/260/280 /
300/300/320/320/340/340/3
40th, 4th and 6th zones are vents open to the atmosphere, rotation speed is 80
rpm, oligomer supply rate 2 kg / hr, exhaust nitrogen purge)
The polycondensation was promoted to increase the molecular weight. The progress is shown in Table 2.

Reference Example 2 In Reference Example 1, 97.0 g of terephthalic acid (0.58
Mol) and 79.4 g (0.48 mol) of isophthalic acid were used to produce a polyamide in the same manner as in Reference Example 1. The results are shown in Table 2.

(Production of concentrated sulfuric acid-insoluble polyamide) Reference Example 3 The polymer obtained in Reference Example 1 was subjected to solid phase polymerization under stirring at 280 ° C and 1 mmHg for 4 hours to increase the molecular weight. The results are shown in Table 2.

Reference Example 4 In Reference Example 1, hexamethylenediamine 129.6
An oligomer was obtained in the same manner as in Reference Example 1 except that g (1.12 mol) was used, and this was polymerized in the same manner as in Reference Example 3. The results are shown in Table 2.

Reference Example 5 In Reference Example 1, 114.7 g of terephthalic acid (0.7
0 mol) and isophthalic acid 61.7 g (0.37 mol)
An oligomer was obtained in the same manner as in Reference Example 1 except that was used, and was polymerized in the same manner as in Reference Example 3. The results are shown in Table 2.

Reference Example 6 232 g (1.40 mol) of terephthalic acid, 241 g (1.4 mol) of 1,10-diaminodecane and ion-exchanged water 10
Was charged into a 10-volume reactor equipped with a stir bar, a thermometer, and a reflux condenser, and reacted under a nitrogen atmosphere at a temperature of 95 to 100 ° C. for 1 hour. After the reaction was completed, the transparent solution was air-cooled, and the precipitated nylon salt was collected by suction filtration to obtain 100
After drying at 100 ° C and 100 mmHg, 450 g of terephthalic acid-1,10-diaminodecane and nylon salt were obtained.

450 g (1.33 mol) of this nylon salt was charged into a 1-capacity reactor, the pressure was reduced to 1 mmHg, the atmosphere in the reaction vessel was replaced with nitrogen, and the mixture was reacted at 300 ° C. for 1.5 hours in a nitrogen stream to produce water. Terephthalic acid-1,10
-390 g of an oligomer consisting of diaminodecane are obtained.
The [η] measured in concentrated sulfuric acid at 30 ° C. was 0.45 dl / g.

This polyamide was crushed by a crusher (passed through 32 meshes), dried at 80 ° C. and 50 mmHg for 12 hours, and then solid-phase polymerized at 300 ° C. and 0.7 mmHg for 10 hours to give terephthalic acid- A polyamide composed of 1,10-diaminodecane was obtained. The results are shown in Table 2.

Example 1 With respect to 100 parts by weight of the polyamide described in Reference Example 1,
0.5 parts by weight of Irganox 245 (manufactured by Ciba Geigy) was dry blended in nitrogen to prepare a polyamide composition. Table 3 shows the physical properties of test pieces prepared using this composition.

Examples 2 to 6 and Comparative Examples 1 to 4 Polyamides as in Example 1 except that the polyamides listed in Table 3 and the stabilizers listed in Table 3 were used in the amounts listed in Table 3. A composition was made. Table 3 shows the physical properties of test pieces prepared using these compositions.

Claims (2)

[Claims] 1. A terephthalic acid component unit of (A) (a) is 60 to
It is in the range of 100 mol% and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is 0 to 40 mol%.
A aromatic dicarboxylic acid component unit in the range of (b) and (b) a polyamide comprising an aliphatic alkylenediamine component unit having 6 to 18 carbon atoms, and (B) a range of 0.1 to 5% by weight with respect to the polyamide. In general formula (I) (However, X represents an ester bond, R ¹ and R ² each independently represent an alkyl group, and R ³ and R ⁴ represent an alkylene group having 1 to 10 carbon atoms.) A polyamide composition comprising: 2. The (A) (a) terephthalic acid component unit is 60 to
It is in the range of 100 mol% and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is 0 to 40 mol%.
A aromatic dicarboxylic acid component unit in the range of (b) and (b) a polyamide comprising an aliphatic alkylenediamine component unit having 6 to 18 carbon atoms, and (B) a range of 0.1 to 5% by weight with respect to the polyamide. Formula (II) in (However, X ¹ represents an ester bond, X ² represents an ether bond, R ¹ and R ² each independently represent an alkyl group, R ³
And R ⁴ represent an alkylene group having 1 to 10 carbon atoms. ) A polyamide composition containing an alkyl-substituted phenol-based compound represented by: