JP2001098149A - Polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide resin composition reinforced with an inorganic material excellent in strength/stiffness and excellent in appearance (specular gloss and uniformity of an embossed surface) of molded products and especially excellent in weatherability. SOLUTION: This polyamide resin includes (D) 1-10 pts.wt of carbon black, (E) 0.01-1 pts.wt of a cupper compound and (F) 0-2 pts.wt of an alkali metal halide per 100 pts.wt of the polyamide resin composition reinforced with an inorganic material including (A) a crystalline polyamide resin mainly comprising polycaproamide, (B) a polyamide resin excluding the resin (A) and (C) an inorganic reinforcing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inorganic reinforced polyamide resin composition comprising a polycapramide resin, a polyamide resin other than the polycapramide resin, and an inorganic reinforcing material. Specifically, the composition of the present invention has excellent rigidity and strength,
Also, the present invention relates to an inorganic reinforced polyamide resin composition which is excellent in the appearance of a molded product (mirror surface gloss, textured surface uniformity) and particularly excellent in weather resistance. In particular, it is suitable for automotive exterior parts and door mirror parts.

[0002]

2. Description of the Related Art Generally, polyamide resins have mechanical properties,
It has excellent heat resistance, impact resistance, and chemical resistance, and is widely used in automobile parts, electric parts, electronic parts, household goods, and the like. Above all, polyamide resin to which inorganic reinforcement represented by glass fiber is added, rigidity, strength and heat resistance are greatly improved,
In particular, it is known that rigidity increases in proportion to the amount of addition. However, rigidity,
If a reinforcing material such as glass fiber is added in a large amount of 50 to 70% by weight for the purpose of improving the strength, the appearance of the molded product (mirror surface gloss,
The surface uniformity of the grain surface is extremely reduced, and the commercial value is significantly impaired. Therefore, as a method for improving the appearance of a molded article, it has been proposed to add an amorphous resin to a crystalline polyamide resin. (For example, Japanese Patent Application Laid-Open No. 2-140265)
JP, JP-A-3-9952, JP-A-3-269
056, JP-A-4-202358)

However, these methods do not provide good mirror surface gloss and uniform surface gloss. Also, a method is known in which a semi-aromatic polyamide resin (MXD-6) is highly filled with nylon 66, glass fiber, and mica to increase strength and rigidity (for example, JP-A-1-263151). In such a case, it was necessary to increase the mold temperature during molding to as high as 135 ° C., or even when the temperature was increased, a good appearance of a molded product could not be obtained.

[0004]

Accordingly, the present invention does not deteriorate the appearance of a molded product even when a reinforcing material such as glass fiber is added in a large amount of 50% by weight or more for the purpose of improving strength and rigidity to a polyamide resin. Another object of the present invention is to make it possible to provide a good molded product having a mold temperature of 100 ° C. or less while simultaneously satisfying both strength and rigidity and having excellent weather resistance.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, they have formulated a polycapramide resin, a polyamide resin other than the polycapramide resin, and an inorganic reinforcing material, and have a specific type. It has been found that the above objects can be achieved by adding an amount of the weather resistance improving agent, and the present invention has been finally completed.

That is, the present invention relates to (A) a crystalline polyamide resin containing a polycapramide resin as a main component, (B) (A)
With respect to 100 parts by weight of an inorganic reinforced polyamide resin composition containing a polyamide resin other than the above and (C) an inorganic reinforcing material,
A polyamide resin composition comprising (D) 1 to 10 parts by weight of carbon black, (E) 0.01 to 1 part by weight of a copper compound, and (F) 0 to 2 parts by weight of an alkali metal halide compound, and The inorganic reinforced polyamide resin composition composed of the components (A), (B) and (C) has a melt flow index (MFI) of 4.0 g / 10 min at a moisture content of 0.05% or less. The polyamide resin composition as described above, wherein the cooling crystallization temperature (TC2) measured by a differential scanning calorimeter (DSC) is (TC2) ≦ 185 ° C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The component (A) in the present invention is a polycapramide resin usually obtained by polycondensation of ε-caprolactam called nylon 6, and the relative viscosity of a commonly used molding material measured by 96% -H ₂ SO ₄ is 2%. , But the relative viscosity when used in the present invention is 1.
The range of 7 to 2.2 is preferred. Particularly preferred is 1.9.
~ 2. 1 range. If it is less than 1.7, the toughness decreases, and if it exceeds 2.2, the fluidity decreases, and the desired appearance of the molded product cannot be obtained. However, it is more realistic to regulate the melt flow index of the inorganic reinforced polyamide resin than to regulate the relative viscosity of nylon 6.

The polyamide resin other than the polycapramide resin as the component (B) in the present invention is defined as a polyamide resin obtained from adipic acid, terephthalic acid, isophthalic acid, trimethylhexamethylenediamine, hexamethylenediamine, metaxylylenediamine, or ε-caprolactam. It is united. Specific examples include hexamethylene diamine and adipic acid polymer, hexamethylene diamine and terephthalic acid polymer,
Hexamethylenediamine and isophthalic acid polymer, hexamethylenediamine and terephthalic acid and isophthalic acid polymer, hexamethylenediamine and terephthalic acid and adipic acid polymer, hexamethylenediamine and terephthalic acid and ε-caprolactam polymer, meta-xylylenediamine And adipic acid polymer, trimethylhexamethylenediamine and terephthalic acid polymer, trimethylhexamethylenediamine and terephthalic acid and ε-caprolactam polymer, trimethylhexamethylenediamine and terephthalic acid, isophthalic acid polymer, terephthalic acid and isophthalic acid and hexaphthalic acid Copolymers of methylenediamine and ε-caprolactam, and copolymers of metaxylylenediamine with terephthalic acid and isophthalic acid with ε-caprolactam, are particularly limited. Not intended to be. The relative viscosity of these polyamide resins is not particularly limited, but the preferred range is 1.8 to 2.4.

The total amount of the components (A) and (B) added is 30 to 55% by weight, preferably 35 to 50% by weight, based on the total composition. Further, the mixing ratio of the component (A) and the component (B) is not particularly limited, but the addition amount of the component (B) is preferably 8 to 18% by weight based on the total addition amount of the component (A) and the component (B). . If the added amount of the component (B) is too small, a good appearance of the molded article cannot be obtained. Conversely, if the added amount of the component (B) is too large, the solidification of the molded article will be poor, resulting in mold release failure or heat during molding. Or the rigidity between them decreases.

The component (C) in the present invention is an inorganic reinforcing material. Specific examples thereof include a fibrous inorganic reinforcing material such as glass fiber, acicular wollast, whisker, carbon fiber and ceramic fiber, silica, alumina and talc. , Kaolin, quartz, glass, mica, graphite, and other powdery inorganic reinforcing materials. Preferred inorganic reinforcing materials include glass fiber, powdered glass (milled fiber), mica, talc, kaolin, acicular wollast, and the like. These inorganic reinforcements can be used alone or
More than one species can be used in combination. In addition, when these inorganic reinforcements are used for reinforcement of polyamide resin,
As the surface treatment agent, those generally treated with aminosilane may be used.

The amount of the component (C) is from 45 to 70% by weight, preferably from 40 to 65% by weight.
If the added amount of the component (C) is less than 45% by weight, the strength and rigidity are reduced.

Further, when the water content of the inorganic reinforced polyamide resin composition of the present invention is 0.05% or less, the melt flow index is 4.0 g / 10 minutes or more, and the temperature is lowered by a differential scanning calorimeter (DSC). The crystallization temperature (TC2)
It is preferable that (TC2) ≦ 185. The melt flow index in the present invention is JIS K-721.
It is a value measured at 275 ° C. × 2160 g load according to 0. Further, the measurement of the cooling crystallization temperature (TC2) was carried out by using a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min to 300 ° C. in a nitrogen stream, and the temperature was maintained for 5 minutes. Thereafter, the temperature was measured by lowering the temperature to 100 ° C. at a rate of 10 ° C./min. 3. Melt flow index is 4.
If it is less than 0 g / 10 minutes, it is difficult to obtain a good appearance of the molded product, which is not preferable.

In order to obtain an inorganic reinforced polyamide resin composition having a melt flow index of 4.0 g / 10 min or more in the present invention, a relative viscosity of 2.3, which is commonly used, is usually used.
When the above-mentioned crystalline polyamide resin is used, a crystalline polyamide resin having an ultra-low viscosity (relative viscosity of 1.7 to 2.2) which does not reach the melt flow index range (less than 4.0 g / 10 minutes) is used. Alternatively, a prescription such as adding a polyamide resin molecular chain scissor at the time of compounding may be employed. Chain breaking agent (thickening agent) for the polyamide resin
Examples thereof include aliphatic dicarboxylic acids and aromatic dicarboxylic acids, and specific examples thereof include oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, terephthalic acid, and the like. However, there is no particular limitation. In addition, the addition amount is (A) +
0.1 to 100 parts by weight of the total of the components (B) and (C)
At around 3 parts by weight, the melt flow index of the composition of the present invention becomes 4.0 g / 10 minutes or more. However, the effect of the molecular chain scission agent varies depending on the compound processing conditions. Naturally, the higher the processing temperature and the longer the polymer residence time during compounding, the better the effect. Generally, the compounding temperature is generally in the range of 240 to 300 ° C., and the polymer residence time during compounding is generally within 15 to 60 seconds. Further, the cooling crystallization temperature (TC2)
If (TC2) ≦ 185 is not satisfied, it is difficult to obtain a good appearance of the molded article due to the crystallization rate of the composition, which is not preferable.

As the weather resistance improving agent in the present invention,
(D) 1 to 10 parts by weight of carbon black, and (E) 0.01 to 1 part by weight of a copper compound, based on 100 parts by weight of the inorganic reinforced polyamide resin composition composed of (A), (B) and (C). And (F) an alkali metal halide compound 0 to 5
Contains parts by weight.

In the present invention, the addition amount of the carbon black as the component (D) is based on 100 parts by weight of the inorganic reinforced polyamide resin composition composed of (A), (B) and (C).
Usually, it is 1 to 10 parts by weight, but preferably 2 to 9 parts by weight. If the addition amount of carbon black is 1 part by weight or less, the effect on weather resistance is small, which is not preferable.

Specific examples of the copper compound (E) in the present invention include cuprous chloride, cuprous bromide, cuprous iodide, cupric chloride, cupric bromide, and iodine. Copper salts of organic carboxylic acids such as cupric chloride, cupric phosphate, cupric pyrophosphate, copper sulfide, copper nitrate, and copper acetate can be used. These copper compounds may be used alone or in combination of two or more. The amount of the copper compound is usually 0.01 to 100 parts by weight of the inorganic reinforced polyamide resin composition composed of (A), (B) and (C).
To 1 part by weight, preferably 02 to 0.8 part by weight.

Specific examples of the alkali metal halide compound (F) in the present invention include lithium chloride, lithium bromide, lithium iodide, lithium fluoride, sodium chloride, sodium iodide, potassium chloride, and odor. Potassium iodide, potassium iodide, potassium fluoride and the like. Of these, potassium iodide is particularly preferred. These alkali metal halide compounds may be used alone or in combination of two or more. The addition amount of these alkali metal halide compounds is usually 0 to 2 parts by weight based on 100 parts by weight of the inorganic reinforced polyamide resin composition composed of (A), (B) and (C).

In addition to the above, the inorganic reinforced polyamide resin composition of the present invention may further comprise a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, a lubricant, a crystal nucleating agent, if necessary. A release agent, an antistatic agent, a flame retardant, a pigment, a dye, or another polymer may be added.

As a method of obtaining the composition of the present invention, the components (A), (B), (C), (D), (E) and (F) are mixed in the above-mentioned mixing ratio in an arbitrary mixing order. , Melt-mixed. The melt mixing method can be any method known to those skilled in the art, such as a single screw extruder, a twin screw extruder, a kneader,
Banbury mixers, rolls, etc. can be used. Among them, it is preferable to use a twin-screw extruder. In addition, glass fibers, needle-like wollasts, and the like, which are easily broken during extrusion processing, are preferably introduced through the side opening of the twin-screw extruder, but are not particularly limited.

[0020]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. The properties and physical properties shown in the following examples and comparative examples were measured by the following test methods.

(1) Relative viscosity (sulfuric acid solution method): JIS
In accordance with K-6810, measured at 96% -H ₂ SO ₄ solution. (2) Tensile strength: Measured according to ASTM D-638. (3) Tensile modulus: Measured according to ASTM D-638. (4) Specular gloss: 100 × 100 × 3 mm with mirror finish
t mold, resin temperature 280 ° C, mold temperature 80 ° C
And a gloss at an incident angle of 60 ° was measured according to JIS Z-8714 (the higher the numerical value, the better the gloss). Judgment: glossiness 92 or more: 、, glossiness 91 to 7
5: Δ, glossiness 74 or less: ×. (5) Uniform surface quality of the grain surface: A plate-shaped metal mold subjected to grain processing (a plan view is shown in FIG. 1; hatched portions in FIG. 1 are portions where the resin is not inserted) is used.
After molding at 5 ° C. and a mold temperature of 80 ° C. to form a molded product having a thickness of 2.5 mmt, the surface properties of the grained surface were visually determined. Judgment criterion: 印: The transferability of the grain was good over the entire surface and there was no gloss unevenness. Δ: Partially different grain transferability, with slight gloss unevenness. X: Partially greatly different in grain transferability, markedly uneven gloss, cannot be used as exterior parts. (6) Weather resistance: Sunshine weatherometer (SWO)
M), black panel temperature 63 ° C, humidity 50%
RH, spray cycle: A test was conducted at 120 minutes of irradiation / 18 minutes of rainfall, and the gloss of a molded product after 500 hours of irradiation was measured. Judgment: glossiness 50 or more: ○, glossiness 4
9 to 30: Δ, glossiness 29 or less: x

Examples 1-4, Comparative Examples 1-3 Nylon 6 having a different relative viscosity was used as a crystalline polyamide resin, and nylon 66, hexamethylene terephthalate / polyamide resin was used as a polyamide resin other than the crystalline polyamide resin.
Hexamethylene isophthalate (6T / 6I resin), trimethylhexamethylenediamine, terephthalic acid and ε-
A caprolactam polymer (TMD-T resin) was used. As the inorganic reinforcing material, commercially available glass fiber (RES03T-TP64T, Nippon Sheet Glass Co., Ltd.) was used. As the milled fiber, REV-8 (fiber diameter 13 μm, average fiber length 70 μm, surface treatment, Nippon Glass Fibers Co., Ltd.) was used. Agent aminosilane) was used. As the needle-like wollast, NYGLOS-8 (average fiber diameter 8 μ, average fiber length 13
0 μ), and M-325S (average particle diameter 18 μ, average aspect ratio 2) of Repco Co., Ltd.
0) was used. Carbon black was used as a weather resistance improver, cupric chloride was used as a copper compound, and potassium iodide was used as an alkali metal halide compound. 0.4 parts each of calcium montanate is added as a release agent,
After mixing with the compositions shown in Table 1, the cylinder temperature was 270 ° C. and the screw rotational speed was 70 using a 35φ twin screw extruder.
Compounding was performed at rpm to produce pellets. The obtained pellets were dried at a moisture content of 0.0
After drying to 5% or less, various characteristics were evaluated. Table 1 shows the evaluation results.

[0023]

[Table 1]

[0024]

The polyamide resin composition of the present invention comprises a composition containing a polycapramide resin, a polyamide resin other than the polycapramide resin, an inorganic reinforcing material, and a specific type and amount of a weather resistance improver, and has strength and rigidity. It is possible to supply an inorganic reinforced polyamide resin composition which is excellent in the appearance of the molded product (specular surface gloss and textured surface uniformity) and particularly excellent in weather resistance. The polyamide resin composition of the present invention having such excellent performance is used for automobiles,
Since it can be suitably used for engineering plastics applications such as electric and electronic parts applications, it greatly contributes to the industrial world.

[Brief description of the drawings]

FIG. 1 is a plan view of a mold used when evaluating the uniform surface texture of a textured surface of the composition of the present invention.

Continued on front page F-term (reference) 4J002 CL01W CL03X CL05X DA016 DA026 DD038 DD058 DD077 DD087 DD088 DE146 DF037 DG027 DH047 DJ006 DJ016 DJ036 DJ046 DJ056 DL006 EG047 FA046 FD016

Claims (2)

[Claims] 1. An inorganic reinforced polyamide resin composition containing (A) a crystalline polyamide resin having a polycapramide resin as a main component, (B) a polyamide resin other than (A), and (C) an inorganic reinforcing material, in an amount of 100 parts by weight. On the other hand, (D) 1 to 10 parts by weight of carbon black, (E) 0.01 to 1 part of a copper compound
Parts by weight and (F) an alkali metal halide compound 0
A polyamide resin composition comprising 2 parts by weight. 2. An inorganic reinforced polyamide resin composition comprising the components (A), (B) and (C) has a melt flow index (MF) at a moisture content of 0.05% or less.
I) is 4.0 g / 10 min or more, and the cooling crystallization temperature (TC2) measured by a differential scanning calorimeter (DSC) is
The polyamide resin composition according to claim 1, wherein (TC2) ≤ 185 ° C.