JPH0816192B2 - Polyamide composition - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to polyamide compositions, and more particularly,
In addition to providing excellent heat resistance, mechanical properties, and chemical and physical properties in addition to heat aging resistance,
The present invention relates to a polyamide composition having excellent moldability.

(Prior Art) In general, thermoplastic resins such as polyolefins, polyesters, and polyamides have excellent moldability, so that melt molding such as compression molding, injection molding or extrusion molding can be easily performed, but heat resistance, Since the engineering plastics are not yet satisfactory in both mechanical properties and chemical properties, they are used in their respective general-purpose molding fields by utilizing their respective properties.

On the other hand, polytetrafluoroethylene known as Teflon (registered trademark) and polyparaphenylene terephthalate known as Kevlar (registered trademark) are engineering plastics that are superior in heat resistance, mechanical properties, and chemical-physical properties. Amide, a polyimide composed of a condensate of 4,4'-diaminodiphenyl ether pyromellitic anhydride known as Kapton (registered trademark), polyhexamethylene adipamide known as 6,6-nylon, and trogamide T ( Poly (2,4-trimethylhexamethylene terephthalamide) known as a registered trademark, polyphenylene sulfide, polyacetal and the like are used for various applications.

However, among these, polytetrafluoroethylene, polyparaphenylene terephthalamide, and the above polyimide have excellent heat resistance, mechanical properties, and chemical-physical properties, but since they cannot be melt-molded, The field of use is extremely limited. On the other hand, polyphenylene sulfide, polyhexamethylene adipamide, 2,2,4-trimethylhexamethylene terephthalamide, polyacetal, etc., all have the advantage that they can be melt-molded, on the other hand, Polyphenylene sulfide is inferior in heat resistance properties such as melting point, glass transition point, heat deformation temperature, and mechanical properties such as impact strength and wear resistance.
On the other hand, polyamides such as polyhexamethylene adipamide and 2,4,4-trimethylhexamethylene terephthalamide all have heat resistance characteristics such as glass transition point and heat distortion temperature,
Poor mechanical properties such as tensile strength, bending strength, limiting PV value, wear resistance, etc. and chemical properties such as chemical resistance, boiling water resistance and saturated water absorption. Further, polyacetal is inferior in heat resistance characteristics such as melting point and heat deformation temperature 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 consisted of an aromatic dicarboxylic acid component unit containing an terephthalic acid component unit as a main component and an aliphatic alkylenediamine component unit. It has been found that polyamide has excellent heat resistance, mechanical strength, chemical-physical characteristics, and molding characteristics, and particularly excellent sliding characteristics (Japanese Patent Application No. 59-1204).
No. 0). However, as a result of further diligent research for improving the heat aging resistance of the polyamide, the present inventors further add a predetermined copper compound, preferably a predetermined copper compound and a predetermined alkali metal halide. This has led to the present invention by finding that it is possible to obtain a polyamide composition as a molding material that gives a molded product having excellent heat aging resistance.

(Structure of the Invention) The first polyamide composition according to the present invention is (A) (a) an aromatic dicarboxylic acid component other than a terephthalic acid component unit in the range of 60 to 85 mol% of a terephthalic acid component unit. A unit comprising an aromatic dicarboxylic acid component unit whose unit is in the range of 15 to 40 mol%, (b) a polyamide comprising an aliphatic alkylenediamine component unit having 6 carbon atoms, and (B) 1 to 1 as a copper metal for the above polyamide. 1000pp
It is characterized by containing a copper compound in the range of m.

The second polyamide composition according to the present invention is characterized in that, in addition to (A) and (B) above, (C) contains an alkali metal halide in the range of 1 to 10,000 ppm with respect to the above polyamide. And

In the polyamide composition according to the present invention, the polyamide (A) comprises (a) a terephthalic acid component unit in the range of 60 to 85 mol% and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit of 15 to 40%. It consists of an aromatic dicarboxylic acid component unit in the range of mol% and (b) an aliphatic alkylenediamine component unit having 6 carbon atoms.

Among the aromatic dicarboxylic acid component units (a), as the aromatic dicarboxylic acid component units other than the terephthalic acid component unit, specifically, components such as isophthalic acid, phthalic acid, 2-methylterephthalic acid, naphthalenedicarboxylic acid, etc. The unit can be exemplified. 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, of the aromatic dicarboxylic acid component unit (a), terephthalic acid accounts for 60 to 85 mol%, and aromatic dicarboxylic acid other than the terephthalic acid component unit is 15 to 40 mol%.
It is necessary to be in the range of mol%. According to the present invention, since the terephthalic acid component unit and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit are within the above range, the obtained polyamide composition has excellent moldability and heat aging resistance. And a heat-deformation temperature and other mechanical properties such as bending strength and abrasion resistance.

In particular, in the aromatic dicarboxylic acid component unit (a), when the terephthalic acid content is less than 60 mol% and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is more than 40 mol%, such a polyamide is used. Molded product obtained from the composition containing heat resistance characteristics including heat aging resistance and heat distortion temperature, tensile strength, bending strength, mechanical characteristics such as wear resistance,
Poor chemical and physical properties such as chemical resistance and water resistance.

On the other hand, in the aromatic dicarboxylic acid component unit (a), terephthalic acid is more than 85 mol% and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is 15 mol%.
When it is less than the above range, the melting point of the obtained polyamide composition is high and it is close to the decomposition point, so that molding is difficult.

However, in the present invention, the aromatic dicarboxylic acid component unit (a) is used together with 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, for example, about 10 mol% of a polycarboxylic 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 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,
Examples of component units include 1,6-diaminohexane.

Of these, a 1,6-diaminohexane component unit is particularly preferably used.

Further, in the polyamide composition according to the present invention, the 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,
Polymer Reviews, 10, Condensation Polymers by Interf
acial and Solution Methods (PWMorgan, Intersc
ience Publishers (1965)) and Makromal.Chem., 47,9
3-113 (1961)), by polycondensing the diacid halide of the aromatic dicarboxylic acid, which is the above-mentioned polyamide constituent unit, and the aliphatic alkylenediamine by a solution method. Obtainable. It can also be obtained by an interfacial polymerization method. Alternatively, it can be obtained by polycondensing the aromatic dicarboxylic acid and the alkylenediamine or the 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.

Furthermore, in the polyamide composition according to the present invention, the polyamide is not only the concentrated sulfuric acid-soluble polyamide,
It has a composition in the same range as this concentrated sulfuric acid-soluble polyamide, but may contain a polyamide insoluble in concentrated sulfuric acid at 50 ° C. Here, the polyamide insoluble in concentrated sulfuric acid at 50 ℃,
One of the polyamides crushed polyamide and passed through 32 mesh
A concentrated sulfuric acid solution having a concentration by weight of 50% was heated and stirred at 50 ° C. for 10 hours, and then filtered with a 2G glass filter at a temperature of 50 ° C.,
It refers to a polyamide from which the soluble portion has been removed. 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.
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, without any limitation, as a method for producing a mixture of concentrated sulfuric acid-insoluble polyamide or concentrated sulfuric acid-soluble polyamide and concentrated sulfuric acid-insoluble polyamide, for example, a method of further solid-state 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 34
0 ° C. or higher, polycondensation of alkyne diamine and aromatic dicarboxylic acid with a charge molar ratio of 1.03 or higher, polycondensation of alkylenediamine and aromatic dicarboxylic acid, and trifunctional 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 concentrated sulfuric acid-soluble polyamide. Particularly, according to the present invention, 100 parts by weight of concentrated sulfuric acid-soluble polyamide is mixed with 2 parts of concentrated sulfuric acid-insoluble polyamide.
When it is contained in an amount of ˜100 parts by weight, preferably 3 to 600 parts by weight, and particularly preferably 5 to 400 parts by weight, 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 crushed 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, respectively, and dried, and the weight of each is measured.

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 to the polyamide is 1 to 1000 ppm, preferably 10 to 100.
It is compounded in the ppm range. When the compounding amount of the copper compound is less than 1 ppm as copper metal with respect to the polyamide,
Improving the heat aging resistance of the molded product obtained from such a polyamide composition is not yet sufficient, while 1000 ppm as copper metal
When a large amount is mixed beyond the above range, the mechanical strength such as tensile strength and bending strength will decrease.

In particular, according to the present invention, when the copper compound is used in combination with an alkali metal halide in a polyamide, a molded product obtained from such a polyamide has markedly superior heat aging resistance.

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. Among them, potassium iodide is particularly preferable because it has excellent effects.

The amount of the alkali metal halide compounded is 1 to 10,000 ppm, preferably 10 to 5000 ppm, relative to the polyamide. Similar to the case of the copper compound, when the amount of the alkali metal halide compounded is less than 1 ppm with respect to the polyamide, the effect of improving the heat aging resistance of the molded product by the addition of the alkali metal halide is still poor, on the other hand, 10000ppm
If a large amount is exceeded, the mechanical strength at room temperature such as tensile strength and bending strength will decrease. Further, in the present invention, a copper composition and an alkali metal halide compound may be added to the raw materials for polycondensation to obtain a polyamide composition.

In the polyamide composition according to the present invention, in addition to the above-mentioned copper compound and alkali metal halide, if necessary, a conventionally known polymer, stabilizer, plasticizer,
It may contain a release agent, a lubricant, a filler and the like. Examples of the polymer include polyamides such as nylon 66 and nylon 6 and the like.

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

As the inorganic filler, for example, silica, alumina,
Silica-alumina, talc, diatomaceous earth, clay, kaori, quartz, glass, mica, graphite, molybdenum disulfide, gypsum, red iron oxide, titanium dioxide, zinc oxide, aluminum, copper, stainless powder, etc. ,
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 Wholly aromatic polyamides such as condensates with isophthalic acid, condensates of para or metaaminobenzoic acid, wholly aromatic polyamideimides such as condensates of diaminodiphenyl ether and trimellitic anhydride and / or pyromellitic acid, all Heterocycle-containing polymers such as aromatic polyimide, polybenzimidazole, polyimidazophenanthroline, powdered materials such as polytetrafluoroethylene, plate-shaped materials, fibrous materials or cross-shaped products as secondary processed products thereof. I can list things.

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 a powdery material, silica,
Silica-alumina, alumina, titanium dioxide, graphite, molybdenum disulfide, polytetrafluoroethylene and the like are preferably used, but in particular, graphite, molybdenum disulfide and polytetrafluoroethylene are used for dynamic friction of molded articles obtained from the composition. Coefficient, Taber wear, limit
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 200 parts by weight or less, preferably 100 parts by weight with respect to 100 parts by weight of the polyamide composition.
In the range of 0.5 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 1
It is preferred to have an average length in the range of ~ 10 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 is a usual melt molding,
For example, it can be molded by compression molding, injection molding or extrusion molding.

(Effect of the invention) As described above, the polyamide composition according to the present invention comprises a polyamide predetermined copper compound having a predetermined composition, or a polyamide having a predetermined composition, a predetermined copper compound, and a predetermined alkali metal halide. The molded product obtained by containing such a polyamide composition has remarkably improved heat aging resistance. Of course, heat resistance characteristics such as 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, chemistry such as saturated water absorption rate, etc. Physical properties, fluidity of melted composition, melt compression moldability, melt injection moldability, melt extrusion moldability, and other molding characteristics.

(Examples) 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.

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

(Polyamide composition, preparation of test pieces and evaluation of physical properties) Polyamide was crushed by a crusher (passed through 32 mesh), dried at 100 ° C and 1 mmHg for 12 hours, and a predetermined amount of copper compound and alkali metal halide. Was dry blended in nitrogen to obtain a polyamide composition.

Next, such a polyamide composition was hot-pressed at a temperature 20 ° C higher than the melting point of the polyamide under a pressure of 100 kg / cm ^{2 in} a nitrogen atmosphere by a press molding machine, and then at 20 ° C.
Cold pressing was performed at a temperature of 2 to prepare a compression molded plate having a thickness of 2 to 4 mm. These molded plates were cut into test pieces having the dimensions shown in Table 1, then left in an atmosphere of 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 flexural strength after the flexural test piece was stored in an air oven at 250 ° C. for 2 days and its retention rate with respect to the initial value.

In addition, the glass fiber-containing molded product was 60 parts by weight of crushed and dried polyamide and 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, 20mm
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 blended to prepare a test piece.

Reference Example 1 123.6 g (0.744 mol) of terephthalic acid, 52. of isophthalic acid.
9g (0.318 mol) hexamethylenediamine 123.4g (1.06
Mol) and ion-exchanged water (33 g) were charged into a 1-volume autoclave, and after sufficiently purging with nitrogen, the temperature was raised to 280 ° C. with stirring for 2 hours. Furthermore, 2 in the sealed state
After allowing the reaction to proceed at 80 ° C. for 1 hour, 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.

This oligomer is a twin-screw extruder (Screen diameter 30 mm, L /
D = 42, barrel temperature (℃) 30/260/280/300/300/320/320 /
In the 340/340/340, 4th and 6th zones, the polycondensation was promoted by an atmosphere open vent, a rotation speed of 80 rpm, an oligomer supply rate of 2 kg / hour, and an exhaust gas was a nitrogen purge) to obtain a high molecular weight. The results are shown in Table 2.

Reference Example 2 In Reference Example 1, terephthalic acid 97.0 g (0.58 mol)
A polyamide was produced in the same manner as in Reference Example 1 except that 79.4 g (0.48 mol) of isophthalic acid was used. Second result
Shown in the table.

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

Reference Example 4 In Reference Example 1, hexamethylenediamine 129.6 g
An oligomer was obtained in the same manner as in Reference Example 1 except that (1.12 mol) was used, and 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 (0.70 mol) of terephthalic acid
And using 61.7 g (0.37 mol) of isophthalic acid,
An oligomer was obtained in the same manner as in Reference Example 1 and was used as Reference Example 3.
Higher molecular weight was obtained in the same manner as in. The results are shown in Table 2.

Reference Example 6 Hexamethylenediamine 123.4 g (1.06 mol), terephthalic acid 158.0 g (0.952 mol) and isophthalic acid 17.6 g (0.
(106 mol) under the same conditions as in Reference Example 1,
An oligomer having an [η] of 0.15 dl / g (measured in concentrated sulfuric acid at 30 ° C) was obtained.

The oligomer is then added to the barrel temperature (30/260/290/3
20/350/50/350/350/350/350).

The [η] (measured in concentrated sulfuric acid at 30 ° C.) of the obtained polyamide was 1.20 dl / g, and the melting point was 355 ° C.

Example 1 To the polyamide described in Reference Example 1, cupric chloride and potassium iodide were added at 3 ppm (as Cu) and 1400 pp, respectively.
m was dry-blended in nitrogen to prepare a polyamide composition. Table 3 shows the physical properties of test pieces prepared using this composition.

Examples 2-7 and Comparative Examples 1-8 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
An aromatic dicarboxylic acid component unit in the range of 85 mol% and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit in the range of 15 to 40 mol%, and (b) having 6 carbon atoms.
Of the aliphatic alkylenediamine component unit of (1), and (B) 1 to 1000 pp as a copper metal with respect to the above polyamide.
A polyamide composition comprising a copper compound in the range of m. 2. The (A) (a) terephthalic acid component unit is 60 to
An aromatic dicarboxylic acid component unit in the range of 85 mol% and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit in the range of 15 to 40 mol%, and (b) having 6 carbon atoms.
A polyamide comprising the aromatic alkylenediamine component unit of (B) 1 to 1000 pp as copper metal with respect to the above polyamide
A polyamide composition comprising a copper compound in the range of m, and (C) an alkali metal halide in the range of 1 to 1000 ppm with respect to the above polyamide.