JPH0632979A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin compsn. excellent in the strengths and rigidity after water absorption and also excellent in dimensional stability, surface appearance, light resistance, etc., by incorporating an Mn compd. and/or a mixture of a Cu compd. with an I compd. in a specified amt. into a specific polyamide. CONSTITUTION:An Mn compd. (e.g. manganese lactate) in an amt. satisfying the equation: 0.5ppm<=Mn<=60ppm and/or a mixture of a Cu compd. (e.g. copper acetate) with an I compd. (e.g. KI) in amts. satisfying the equations: 0.5 ppm<=Cu<=150ppm and 20<=I/Cu (molar ratio)<=30 is incorporated into a polyamide which comprises 30-95wt.% hexamethyleneisophthalamide units, 0-40wt.% hexamethyleneterephthalamide units, and 5-30wt.% hexamethyleneisophthalamide units and has a ratio of the terminal COOH groups to all the terminal groups of 65% or higher.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is capable of stably obtaining a resin molded product having excellent mechanical properties, particularly strength, rigidity and dimensional stability when absorbing water, and having good surface appearance and weather resistance. The present invention relates to a crystalline polyamide resin composition useful as a structural material for automobiles. The exterior structural material refers to a mechanical component or a structural component that is required to have a surface finish of a molded article (for example, texture finish, high surface gloss, etc.) and a relatively large strength and rigidity. For example, desk legs, chair legs,
Furniture parts such as seats, cabins and wagons, OA equipment field products such as notebook computer housings, door mirror stays, wheel rims, wheel caps, wipers, motor fans, seat lock parts, gears, lamp housings and other automotive parts, Electric field products such as pulleys, gears, hot-air fan housings, and other field products such as wheel rims, wheel spokes, saddles, saddle posts, handles, stands, luggage parts, and other bicycle parts, valve housings, nails, screws, bolts, bolts and nuts. Etc.

[0002]

2. Description of the Related Art Polyamide resins are excellent in mechanical properties such as tensile strength, bending strength and elastic modulus, and also have good heat resistance and chemical resistance. Therefore, they are used in many fields such as precision machine parts and structural materials. Has been done.

However, when the polyamide is an aliphatic polyamide (for example, nylon 66, nylon 6, nylon 46), the use thereof is limited because the strength and rigidity are lowered by water absorption and the dimensional change is remarkable. .

In order to solve this problem, a study has been made to increase the rigidity and suppress the water absorption by using a polyamide containing an aromatic component (nylon 6I, nylon 6I / 6T copolymer, nylon 66 / 6T copolymer, etc.). (For example, Japanese Patent Publication No. 3-56576, Japanese Patent Publication No. 3-7721)
6 etc.). Among the polyamides containing these aromatic components, in the case of crystalline polyamides, the melting point is too high to be melt-molded only within a very limited temperature range and residence time, and those with a high glass transition point are sufficiently crystallized. In addition, a high temperature mold equipped with an oil temperature controller etc. was required. Amorphous polyamides have also not been practically used because of problems such as poor fluidity during molding, long molding time cycle, poor productivity, and poor chemical resistance. Further, the above-mentioned aromatic polyamide has a defect that the mold transfer property is poor because of a high solidification rate, and unevenness in surface gloss occurs in, for example, surface-texture processing, resulting in an extremely poor surface appearance.

Further, structural materials which are mainly required to have appearance are naturally required to have light (weather) resistance. Japanese Unexamined Patent Publication No. 4-149234 discloses a 66 / 6T / 6I type polyamide resin, which has low water absorption, dimensional stability,
Although it is a resin excellent in surface appearance, it does not have sufficient resistance to (light) weathering and is unsuitable as a structural material requiring appearance.

As a method of increasing the light resistance (weathering resistance) of polyamide, a method of adding a compound such as carbon black, copper, manganese, phosphorus, benzophenone or hindered amine to polyamide is known. Of these, copper compounds that are effective not only in light (weathering) resistance but also in preventing thermal oxidative deterioration are often used, and their properties improve with the amount of copper compound added. However, a polyamide containing a copper compound has a problem of yellowing over time, which causes discoloration of the appearance color of a molded product, so that the amount used is limited and sufficient light resistance (weathering) cannot be obtained. There was a problem. That is, strength and rigidity when absorbing water, dimensional stability,
Until now, no material has been excellent in both surface appearance and sufficient light (weathering) resistance.

[0007]

SUMMARY OF THE INVENTION In view of these circumstances, the object of the present invention is to provide mechanical properties, especially strength and rigidity at the time of absorbing water,
It is intended to provide a molding material having excellent dimensional stability, surface appearance, weather (light) resistance and the like.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific aromatic group can be formed by copolymerizing nylon 66 with a specific aromatic component in a specific ratio. By obtaining a polyamide having a ratio of terminal groups and blending a mixture of a specific copper compound and an iodine compound and / or a manganese compound into the polyamide, the weather resistance is greatly improved without causing discoloration of the surface of the molded article, and further It has been found that a material excellent in strength, rigidity, dimensional stability and surface appearance when absorbing water can be stably obtained.

That is, the present invention provides (1) (a) hexamethylene adipamide (66) units 30 to 95 obtained from adipic acid and hexamethylene diamine.
Wt%, (b) hexamethylene terephthalamide (6T) obtained from terephthalic acid and hexamethylene diamine
A polyamide comprising 0 to 40% by weight of a unit, (c) 5 to 30% by weight of a hexamethyleneisophthalamide (6I) unit obtained from isophthalic acid and hexamethylenediamine, and having a carboxyl group end group ratio of 65% or more. On the other hand, a polyamide resin composition containing a mixture of a copper compound and an iodine compound and / or a manganese compound in a ratio satisfying the following formulas (1) to (3).

(1) 0.5 ppm ≦ copper ≦ 150 ppm (2) 20 ≦ iodine / copper ≦ 30 (molar ratio) (3) 0.5 ppm ≦ manganese ≦ 60 ppm (2) The polyamide resin composition 30 described in (1) It is a polyamide resin composition consisting of ˜95 wt% and an inorganic filler of 5 to 70 wt%.

The polyamide resin composition described in (1) above is useful as an exterior structural material, and the polyamide resin composition described in (2) above is also useful as an exterior structural material. The present invention will be described in detail below.

The crystalline polyamide of the present invention comprises (a) 66 units of 30 to 95% by weight, (b) 6T units of 0 to 40% by weight,
(c) 6I unit 5 to 30% by weight. here,
When the content of 66 units is less than 30% by weight, the glass transition point becomes too high, and further, crystallization becomes slow, so that the appearance is deteriorated due to the deterioration of fluidity and the productivity is deteriorated due to a prolonged molding cycle. If 66 units is higher than 95% by weight,
The melting point and the solidification point become high, and the resin is likely to solidify in the mold during molding.For example, in the case of inorganic fiber reinforced molded products, the inorganic fibers stand out on the surface of the molded product, and the transferability is poor in the molded product with a textured surface. Loses practical value,
Further, the rigidity is remarkably lowered due to water absorption, and the dimensional stability is also deteriorated. More preferable composition ratio of 66 units is 50
~ 80% by weight.

If the 6T unit is higher than 40% by weight, the melting point,
The solidification point becomes too high and molding can be performed only within a very limited molding condition range, or the resin tends to solidify and the appearance of the molded product deteriorates, resulting in no practical value. The amount of 6T units is preferably 5-37% by weight.

If the 6I unit is less than 5% by weight, the melting point and the solidification point become too high, and the appearance of the molded product deteriorates, and the practical value is lost. If the 6I unit is higher than 30% by weight, the glass transition point becomes too high and crystallization becomes slower.
Similar to the above, the appearance and productivity are deteriorated. In addition, the crystallinity is drastically reduced, and the rigidity and chemical resistance under heat deteriorate.

The relative viscosity of these three component crystalline polyamides is 1.7 to 4.5 (1.0 g / d in 95.5% sulfuric acid).
1, measured at 25 ° C.). Preferably a relative viscosity of 1.8
Is about 4.3. When the relative viscosity is lower than 1.7, the mechanical properties of the obtained molded product, especially the tensile and bending properties are low and the product becomes brittle, so that a molded product having excellent rigidity, which is one of the objects of the present invention, can be obtained. Absent. When the relative viscosity is higher than 4.3, the fluidity at the time of molding is poor, and no matter how the composition is controlled to the above composition ratio, a molded article having a good appearance can no longer be obtained at the time of molding.

The material of the present invention may be exposed to sunlight or the light of a fluorescent lamp depending on the application, and is required to have sufficient light (weathering) resistance. Therefore, a material having an extremely high level of light resistance (weathering) as compared with conventional polyamide materials is required, and the inventors of the present invention have diligently studied in consideration of that point, and as a result, a mixture of a copper compound and an iodine compound. And / or a manganese compound has the following formula (1) for a polyamide having a carboxyl group end group ratio of 65% or more:
It has been found that a material having extremely high resistance to light (weathering) can be obtained without causing discoloration of the appearance of the molded product, if it is compounded so as to satisfy (3).

(1) 0.5 ppm ≤ copper ≤ 150 ppm (2) 20 ≤ iodine / copper ≤ 30 (molar ratio) (3) 0.5 ppm ≤ manganese ≤ 60 ppm Here, the terminal group ratio of the carboxyl group is { [COO
H] / ([COOH] + [NH ₂ ])} × 100 (%)
It is the value calculated by. When the compounding amount is larger than the values shown in (1) to (3), yellow-green discoloration on the surface of the resin molded product becomes noticeable, and especially when the resin is colored with a coloring agent, the color tone changes over time, resulting in a commercial value. Disappears. On the other hand, if the amount is too small, sufficient light (weather) resistance cannot be obtained. The preferred range is (1) '0.7 ppm≤copper≤100 ppm (2) '22 ≤iodine / copper≤28 (molar ratio) (3)' 0.7 ppm≤manganese≤55 ppm. In the present invention, it is preferable to use the mixture of the copper compound and the iodine compound together with the manganese compound, but it is also possible to use only the mixture of the copper compound and the iodine compound or the manganese compound alone. If the carboxyl group ratio is less than 65%, the yellowish green discoloration on the surface of the resin molded product becomes noticeable. The manganese compound is preferably added when light (weather) resistance is required. There is no particular problem if manganese is added in excess of 60 ppm, but it is not necessary to add manganese in excess of 60 ppm because sufficient weather resistance can be obtained by combination with a copper compound and an iodine compound.

Examples of the copper compound include copper chloride, copper bromide, copper iodide, copper phosphate, copper ammonium complex, copper stearate, copper montanate, copper adipate, copper isophthalate, copper terephthalate, and benzoic acid. Examples of iodine compounds such as copper acid copper, copper pyrophosphate, copper acetate, and ammonia copper include potassium iodide, magnesium iodide, ammonium iodide, and the like, and examples of manganese compounds include manganese lactate and manganese pyrophosphate. These compounds may be added at the time of polymerizing the polyamide, or may be melt-kneaded by using a usual uniaxial or biaxial extruder.

The method for polymerizing the crystalline polyamide of the present invention is not particularly limited, and melt polymerization, solution polymerization, interfacial polymerization, bulk polymerization,
Solid phase polymerization and methods combining these can be used, but in general, melt polymerization or a combination of melt polymerization and solid phase polymerization is suitable.

The inorganic filler in the present invention is glass fiber, carbon fiber, talc, kaolin, mica, wollastonite, calcium carbonate, magnesium carbonate, potassium titanate, etc., the amount of which is 5 to 70 wt%, It is preferably 10 to 65 wt%. If the amount of the inorganic filler is more than 70% by weight, the glossiness of the surface of the molded article will be deteriorated, and if it is less than 5% by weight, the foreign matter effect will be caused and the physical properties will be deteriorated. Among these, glass fiber and carbon fiber are preferable. The inorganic filler may be compounded by melt mixing using a conventional single-screw or twin-screw extruder.

A heat stabilizer, an antioxidant, a flame retardant, a lubricant, a release agent, a nucleating agent, a pigment, a dye, etc. may be added within a range not impairing the object of the present invention, and other may be added depending on the case. It may be blended with the polyamide resin or other resin.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The scope of the present invention is not limited to the examples.

The evaluations in Examples and Comparative Examples were carried out by the following methods.

Relative viscosity: The polymer was dissolved in 95.5 ± 0.03% sulfuric acid at a concentration of 1.0 g / dl, and the temperature was 25 ° C.
It was measured with an Ostwald viscosity tube.

Amino end group: The polymer was dissolved in a 90% aqueous phenol solution and potentiometrically titrated with 1/40 N hydrochloric acid. (40 ° C.) Carboxyl end group: The polymer was dissolved in benzyl alcohol and titrated with a 1/10 N KOH ethylene glycol solution. Phenolphthalein was used as an indicator. (170 ° C.) Tensile property: Conducted according to ASTM D638.

Bending property: Performed according to ASTM D790.

Appearance: The non-reinforced resin was injection-molded using a textured mold, and the uniformity of grain transfer on the surface of the obtained molded product was visually judged. The GF-reinforced product was injection molded using a flat plate mold having a smooth surface, and the presence or absence of GF floating on the surface of the obtained molded product was visually determined.

Light resistance (weather): A test piece was put in a sunshine weatherometer (63 ° C., 18 minutes out of 2 hours. Light source was a xenon lamp) and the time until surface cracking was examined. It was

Example 1 Equimolar salt of adipic acid and hexamethylenediamine 1.2
5 kg, 0.75 kg of equimolar salt of terephthalic acid and hexamethylenediamine, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine, 2 mol% excess of adipic acid and copper acetate with respect to total acid content as copper components 15pp
m, potassium iodide as an iodine component of 375 ppm,
10 ppm of manganese lactate as a manganese component was added, 2.5 kg of pure water was charged into an autoclave having an internal volume of 5 L, and after sufficiently substituting with nitrogen, the temperature was raised from room temperature to 220 ° C. over about 1 hour while stirring. . 18 pressure
The temperature was raised to 260 ° C. over about 2 hours while removing water from the reaction system while maintaining the kg / cm ^2, and the reaction was completed. After the reaction, the valve was closed and the temperature was cooled to room temperature for about 8 hours to obtain a relative viscosity of 1.38 polymer of about 2 kg. After the obtained polymer was pulverized, it was put into an evaporator having an internal volume of 10 L and subjected to solid phase polymerization at 200 ° C. for 10 hours under a nitrogen stream. Solid phase polymerization gave a relative viscosity of 2.35.

Example 2 Equimolar salt of adipic acid and hexamethylenediamine 2.0
0 kg, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine, 2 mol% excess of adipic acid with respect to the total acid content, and 2.5 kg of pure water as starting materials, except that the same method as in Example 1 was used. A polymer was prepared with. The polymer obtained had a relative viscosity of 2.41. Example 3 Equimolar salt of adipic acid and hexamethylenediamine 1.6
25 kg, 0.375 kg of equimolar salt of terephthalic acid and hexamethylenediamine, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine, 2 for all acidic components
A polymer was prepared in the same manner as in Example 1 except that a mol% excess of adipic acid and 2.5 kg of pure water were used as starting materials. The polymer obtained had a relative viscosity of 2.30.

Example 4 The same 66, 6T, 6I composition as in Example 1 was used, but copper acetate was 35 ppm as the copper component, potassium iodide was 875 ppm as the iodine component, and manganese lactate was 1 as the manganese component.
A polymer was prepared in the same manner by adding 0 ppm.
The polymer obtained had a relative viscosity of 2.35.

Example 5 The same 66,6I composition as in Example 2 was used, with copper acetate being 3 ppm as the copper component and potassium iodide being 75 p as the iodine component.
10 ppm of pm and manganese lactate were added as manganese components, and a polymer was prepared by the same method. The polymer obtained had a relative viscosity of 2.41.

Example 6 The polymer obtained in Example 5 and the glass fiber (03JA416 manufactured by Asahi Fiber Glass Co., Ltd.) were used as a twin-screw extruder (Wern).
melt-kneading under the following conditions using ZSK25 manufactured by er. Set the cylinder temperature of the twin screw extruder to 280 ° C,
The polymer was charged from the hopper at a screw rotation of 100 rpm. The glass fiber was added from Zone 4 by side-feed so that the glass fiber content of the resin composition was 33 wt%. The polymer charging section and the glass fiber charging section were thoroughly purged with N ₂ . Vent vacuum was applied from Zone 6 (650 mmHg). Discharge rate 9.4kg / hr,
The resin temperature was 305 ° C.

The pellets thus obtained were treated with N ₂ at 80 ° C.
It was dried under 24 hours.

Example 7 A polymer obtained in the same manner as in Example 1 (however, copper acetate was added so as to have a copper content of 3 ppm) was mixed with glass fiber in the same manner as in Example 6.

Comparative Example 1 2.5 equimolar salt of adipic acid and hexamethylenediamine
In the same manner as in Example 1 except that 0 kg and copper acetate of 3 ppm as a copper component, potassium iodide of 75 ppm as an iodine component and manganese lactate of 10 ppm as a manganese component were added, and 2.5 kg of pure water was used as a starting material. A polymer was made. The polymer obtained had a relative viscosity of 2.62.

Comparative Example 2 Equimolar salt of adipic acid and hexamethylenediamine 1.3
7 kg, 1.13 kg equimolar salt of terephthalic acid and hexamethylene diamine, 3 ppm of adipic acid and copper acetate in excess of 2 mol% with respect to the total acid content as a copper component, 75 ppm of potassium iodide as an iodine component, and manganese lactate. 2.5 kg of pure water by adding 10 ppm as a manganese component
A polymer was prepared in the same manner as in Example 1 except that was used as the starting material. The polymer obtained has a relative viscosity of 2.30.
Met.

Comparative Example 3 Equimolar salt of adipic acid and hexamethylenediamine 1.2
5 kg, 1.25 kg of isophthalic acid and hexamethylenediamine equimolar salt, 3 ppm of copper acetate as a copper component, 75 ppm of potassium iodide as an iodine component, and 10 ppm of manganese lactate as a manganese component were added, and 2.5 kg of pure water was added. A polymer was prepared in the same manner as in Example 1 except that the starting material was used. The polymer obtained had a relative viscosity of 2.50.

Comparative Example 4 A polymer having the same 66, 6T, 6I composition as in Example 4 was prepared in the same manner as in Example 1 without adding a 2 mol% excess of adipic acid. The relative viscosity of the obtained polymer is 2.
It was 40.

Comparative Example 5 A polymer having the same 66, 6T and 6I composition as in Example 1 was prepared by the same method without adding copper acetate, potassium iodide and manganese lactate. The polymer obtained has a relative viscosity of 2.3.
It was 5.

Comparative Example 6 With the same 66, 6T and 6I composition as in Example 1, copper acetate was added as a copper component in an amount of 160 ppm, potassium iodide was added as an iodine component in an amount of 4000 ppm, and manganese lactate was added as a manganese component in an amount of 10 ppm to obtain 1.5 mol. % Excess adipic acid was added and a polymer was prepared in the same manner as in Example 1.
The polymer obtained had a relative viscosity of 2.50.

Comparative Example 7 Equimolar salt of adipic acid and hexamethylenediamine 0.6
25 kg, equimolar salt of terephthalic acid and hexamethylenediamine 1.125 kg, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine, 2 for all acidic components
3pp as a copper component with a molar excess of adipic acid and copper acetate
m, potassium iodide as an iodine component of 75 ppm, manganese lactate as a manganese component of 10 ppm,
A polymer was prepared in the same manner as in Example 1 except that 2.5 kg of pure water was used as the starting material. The polymer obtained had a relative viscosity of 2.30.

Comparative Example 8 The amount of glass fiber compounded in the polymer obtained in Example 5 was 7
It was extruded so as to be 2%. However, the extrudability was poor and the pellets could not be sampled.

Comparative Example 9 The polymer obtained in Example 5 had a glass fiber content of 3
%, And blended in the same manner as in Example 6.

Comparative Example 10 The polymer obtained in Comparative Example 5 had a glass fiber content of 5
It was mixed in the same manner as in Example 6 such that the content became 0%.

A test piece was prepared from the obtained polymer by using an injection molding machine (PS40E manufactured by Nissei Plastic Industry Co., Ltd.). Molding was performed by setting a cylinder temperature of 290 ° C. and a mold temperature of 80 ° C., and performing a cycle of injection for 10 seconds and cooling for 20 seconds.

The results are shown in Table 1.

[0048]

[Table 1]

[0049]

EFFECTS OF THE INVENTION The composition of the present invention enables mechanical properties, particularly rigidity upon absorption of water, dimensional stability, surface appearance, and light resistance (weather).
A molded product having excellent properties and the like can be obtained.

Claims (2)

[Claims] 1. A. (a) Hexamethylene adipamide (6 obtained from adipic acid and hexamethylenediamine
6) Unit 30 to 95% by weight, (b) Hexamethylene terephthalamide (6T) unit obtained from terephthalic acid and hexamethylenediamine 0 to 40% by weight, (c) Hexamethyleneisophthalate obtained from isophthalic acid and hexamethylenediamine The amide (6I) unit is composed of 5 to 30% by weight, and the end group ratio of the carboxyl group is 65%.
With respect to the above polyamides, B. A polyamide resin composition containing a mixture of a copper compound and an iodine compound and / or a manganese compound in a ratio satisfying the following formulas (1) to (3). (1) 0.5 ppm ≤ copper ≤ 150 ppm (2) 20 ≤ iodine / copper ≤ 30 (molar ratio) (3) 0.5 ppm ≤ manganese ≤ 60 ppm 2. The polyamide resin composition 3 according to claim 1.
A polyamide resin composition comprising 0 to 95 wt% and an inorganic filler 5 to 70 wt%.