JPH11293106A - Reinforced polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reinforced polyamide resin composition having bright metallic color tone, excellent mechanical properties and color-retention in thermal aging and useful for electric and electronic parts, etc., by compounding a polyamide resin, an inorganic filler, metal powder and a pearlescent pigment at specific ratios. SOLUTION: This resin composition is produced by compounding (A) 100 pts.wt. of a polyamide resin such as nylon 6, nylon 66 and copolymerized nylon 6/66 (the relative viscosity is preferably 2.2-5.5) with (B) 1-280 pts.wt. of an inorganic filler, e.g. a nano-dispersed filler such as glass fiber, talc or swollen montmorillonite, (C) 1.4-30 pts.wt. of metal powder such as aluminum powder and (D) 2.1-45 pts.wt. of a pearlescent pigment. The compounding amount of the pearlescent pigment is >=1.5 times that of the metal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reinforced polyamide resin composition, and more particularly to a reinforced polyamide resin composition having a bright metallic color.

[0002]

2. Description of the Related Art Polyamide resins have excellent mechanical properties, heat resistance, chemical resistance, and abrasion resistance.
It has been used as a material to replace metals such as aluminum. As a substitute material for a metal, a polyamide resin having a metallic color is often preferred, and Japanese Patent Application Laid-Open No. 50-39350 discloses a synthetic resin obtained by mixing an aluminum metal powder with a thermoplastic resin such as a polyamide resin. Although a resin molded product is disclosed, the reinforced polyamide resin has a drawback that the molded product has a dull color tone and the color of the molded product changes during heat aging.

As for a resin composition having a metallic luster, Japanese Patent Application Laid-Open No. 50-89443 discloses a resin composition obtained by blending a metal powder and a pearl pigment with a thermoplastic resin. However, even in such a compounding method, when applied to a resin often used in a high-temperature atmosphere such as a reinforced polyamide resin, there is a disadvantage that the color of a molded product is discolored upon heat aging.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reinforced polyamide resin composition having a bright metallic color tone, excellent mechanical properties, and excellent color retention during heat aging.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its gist is as follows.
(A) 100 parts by weight of a polyamide resin, (b) 1 to 280 parts by weight of an inorganic filler, (c) 1.4 to 30 parts by weight of a metal powder, and (d) 2.1 to 45 parts by weight of a pearl pigment. The reinforced pigment resin composition has a pearl pigment content of 1.5 times or more the metal powder content.

Hereinafter, the present invention will be described in detail. As the polyamide resin (a) in the present invention, a lactam having three or more rings, a polymerizable ω-amino acid, or a polyamide obtained by polycondensation of a dibasic acid and a diamine can be used. Examples of lactams having three or more ring members and polymerizable ω-amino acids include ε-caprolactam, aminocaproic acid, enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid,
α-pyrrolidone, α-piperidone and the like.

[0007] Examples of the diamine include hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and meta-xylylene diamine. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, glutaric acid, and the like.

Examples of the polyamide resin include polyamide polymers and polyamide copolymers. Specific examples include nylon 4, nylon 6, nylon 7, nylon 8, nylon 11, nylon 12, nylon 6.6, and nylon 6. .9, nylon 6.10, nylon 6.11,
Nylon 6.12, nylon 6T, copolymer nylon 6 /
6.6, copolymer nylon 6/12, copolymer nylon 6 /
6T, copolymer nylon 6I / 6T and the like, and preferably, nylon 6, nylon 66, copolymer nylon 6/66 and the like. A plurality of types of polyamide resins can be used.

The relative viscosity of the polyamide resin is preferably measured at a concentration of 1% in 98% sulfuric acid and a temperature of 25 ° C.
It is 2-5.5, More preferably, it is 2.3-4.5. If the relative viscosity is too low, the mechanical properties decrease, and if it is too high, the moldability is impaired.

The terminal of the polyamide resin may be capped with a carboxylic acid or an amine, and particularly has 6 to 22 carbon atoms.
And a polyamide resin sealed with a carboxylic acid or an amine. Examples of the carboxylic acid used for sealing include aliphatic monocarboxylic acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid. Examples of the amine used for sealing include aliphatic primary amines such as hexylamine, octylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, and behenylamine. The amount of the carboxylic acid or amine used for sealing is preferably about 30 μeq / g.

The inorganic filler (b) in the present invention may be any one as long as it is used for a polyamide resin, and there is no particular limitation on the average particle size and shape. Specific examples of the inorganic filler include glass fiber, glass flake, talc, kaolin, calcined kaolin, montmorillonite, mica (mica), clay mineral, silica, clay, calcium carbonate, magnesium sulfate, wollastonite, whisker, alumina, Examples include asbestos, carbon fibers, nano-dispersed fillers and modified products thereof. The nano-dispersed filler is a filler that exhibits nano-dispersion when added to a resin and provides high rigidity even when a relatively small amount is added. For example, swelled montmorillonite, swellable mica,
Swellable fluoromica-based minerals as disclosed in JP-A-608, and layered silicates as disclosed in JP-A-9-324047. As the inorganic filler, glass fiber, talc, nano-dispersed filler and the like are preferably mentioned. Inorganic fillers may be used without treatment, but various silane coupling agents, titanium coupling agents, higher fatty acids, higher fatty acids, Those whose surfaces have been treated with fatty acid esters, higher fatty acid amides, higher fatty acid salts or other surfactants can be used.

The compounding amount of the inorganic filler is as follows.
1 to 280 parts by weight with respect to 00 parts by weight. If the amount of the inorganic filler is less than 1 part by weight, the rigidity tends to decrease, and if it exceeds 280 parts by weight, the metallic feeling is reduced.
The compounding amount of the inorganic filler is preferably 2 to 200 parts by weight, more preferably 3 to 150 parts by weight, based on 100 parts by weight of the polyamide resin.

The metal powder (c) in the present invention is not particularly limited as long as it is used for a polyamide resin having a metallic color. Metal powders such as aluminum, iron, gold, silver, zinc, tin, nickel and other metal powders, brass and brass using these metals as substrates,
Examples include alloys and compounds such as stainless steel, and preferably aluminum powder. Further, a small amount of a processing agent such as a grinding aid or an organic solvent for preventing metal powder explosion may be contained in the metal powder. The particle size of the metal powder is preferably several microns to several hundred microns.

The amount of the metal powder is 100
It is 1.4 to 30 parts by weight with respect to parts by weight. If the amount of the metal powder is less than 1.4 parts by weight, discoloration tends to occur during heat aging, and if it exceeds 30 parts by weight, the color tone becomes dull and the bright metallic luster is reduced. The mixing amount of the metal powder is preferably 1.5 to 25 parts by weight, more preferably 2 to 20 parts by weight, based on 100 parts by weight of the polyamide resin.

The pearl pigment (d) in the present invention includes:
It is a pigment that gives the resin a pearly luster and is not particularly limited as long as it is used for a polyamide resin. Specific examples of the pearl pigment include synthetic pearl pigments such as titanium oxide coated with titanium oxide, metal oxide-coated mica such as mica coated with bismuth oxychloride, and natural pearl pigments such as fish scale foil. A colored pearl pigment obtained by further coating a colored pigment on the surface of a pigment synthetic pearl pigment may be used. The particle size of the pearl pigment is preferably from several microns to several hundred microns.

The compounding amount of the pearl pigment is as follows.
It is 2.1 to 45 parts by weight with respect to 0 parts by weight. If the amount of the pearl pigment is less than 2.1 parts by weight, discoloration tends to occur during heat aging, and if it exceeds 45 parts by weight, toughness is reduced. The amount of the pearl pigment is based on 100 parts by weight of the polyamide resin.
Preferably it is 2.5 to 40 parts by weight, more preferably 3 to 35 parts by weight. The amount of the pearl pigment is at least 1.5 times the amount of the metal powder. If the amount of the pearl pigment is less than 1.5 times the amount of the metal powder, it is difficult to obtain a bright metallic color. The amount of the pearl pigment
It is preferably at least 1.8 times the amount of the metal powder, more preferably at least twice the amount of the metal powder.

As a method of blending the metal powder, the pearl pigment and the inorganic filler with the polyamide resin, it can be carried out by any of various known means at an arbitrary stage immediately before molding the final molded article. The simplest method is a method of simply dry blending the polyamide resin and the above-mentioned additive, and the obtained dry blend is formed into pellets by melt mixing extrusion. Also, metal powder more than a predetermined amount,
A desired polyamide resin composition can also be obtained by preparing a master pellet in which a pearl pigment and an inorganic filler are kneaded with a polyamide resin in advance and dry blending the master pellet with a polyamide resin for dilution.

In the reinforced polyamide resin composition of the present invention, pigments, dyes, stabilizers, antistatic agents, inorganic fillers and other known additives can be blended and kneaded.
Further, a thermoplastic resin other than the polyamide resin may be blended within a range that does not impair the effects of the present invention.
The molded article obtained by molding the reinforced polyamide resin composition of the present invention shows a bright metallic luster, and the L value measured by a color difference meter is preferably 50 or more, more preferably 55 or more. It can be obtained by supplying to various molding machines such as injection molding, extrusion molding, blow molding, compression molding and the like, and molding according to a conventional method.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Various evaluations in the following Examples and Comparative Examples were performed according to the following methods. (1) Flexural modulus: performed in accordance with ASTM-D790. (2) Izod impact test: performed according to ASTM-D256. (3) Metallic glossiness: visually evaluated. (4) Brightness: Evaluation was made by measuring the L value with a color difference meter manufactured by Suga Test Instruments Co., Ltd. The larger the L value, the brighter it is. (5) Discoloration during heat aging: Evaluation was performed by measuring ΔE before and after heat aging at 120 ° C. for 400 hours using a color difference meter manufactured by Suga Test Instruments Co., Ltd. The larger the value of ΔE, the greater the discoloration during heat aging.

The raw materials used in the examples and comparative examples are as follows. (6) Polyamide 6 resin: manufactured by Mitsubishi Engineering-Plastics Corporation, grade name 1010J, relative viscosity 2.
5. (7) Polyamide 66 resin: manufactured by DuPont, grade name FE3218, relative viscosity 2.8. (8) Talc: Hayashi Kasei Co., Ltd., trade name Micron White 5
000A. (9) Glass fiber: T28, manufactured by NEC Corporation
3. (10) Swellable mica: Somasif ME-100 manufactured by Corp Chemical Co., Ltd. (11) Aluminum powder: manufactured by Toyo Aluminum Co., Ltd., trade name Miteguro 1000, particle size 2 to 80 microns. (12) Pearl pigment: ME-1 manufactured by Nippon Koken Kogyo Co., Ltd.
00R, particle size 10-60 microns.

[Examples 1 to 4]
After blending the polyamide resin, filler, metal powder and pearl pigment, using a TEX30C type twin screw extruder manufactured by Nippon Steel Corporation, the mixture is melt-mixed at a set temperature of 275 ° C. to pelletize the polyamide resin composition Obtained. The pellets were injection molded according to the respective molded articles, and evaluated for flexural modulus, Izod impact value, metallic glossiness, brightness, and discoloration during heat aging. Table 1 shows the evaluation results.

[0022]

[Table 1]

[Comparative Examples 1 to 6]
After blending the polyamide resin, the filler, the metal powder, and the pearl pigment, various evaluations were performed in the same manner as in Example 1. Table 2 shows the evaluation results.

[0024]

[Table 2]

[0025]

The reinforced polyamide resin composition of the present invention comprises:
It has a bright metallic color, excellent mechanical properties, and excellent color retention during heat aging. In various applications, it is used in various industrial parts, AV products, home appliances, OA equipment, telegraph and telephone parts, and other electrical and electronic parts. , Cover such as engine cover, cylinder head cover, rocker cover,
Auto parts such as door handles, appearance, inner layers, cameras,
It is useful as precision machine parts such as watches and leisure goods such as skis and fishing gear.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masami Suzuki 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Mitsubishi Engineering Plastics Co., Ltd. Technology Center

Claims (6)

[Claims] (1) 100 parts by weight of a polyamide resin:
(B) 1 to 280 parts by weight of inorganic filler, (c) metal powder
A reinforced polyamide resin composition comprising 4 to 30 parts by weight and (d) 2.1 to 45 parts by weight of a pearl pigment, wherein the amount of the pearl pigment is 1.5 times or more the amount of the metal powder. 2. The method according to claim 1, wherein (a) the polyamide resin is nylon 6,
The reinforced polyamide resin composition according to claim 1, wherein the composition is nylon 66 or copolymerized nylon 6/66. (3) The polyamide resin has a relative viscosity of 9
8% sulfuric acid concentration 1%, measured at a temperature of 25 ℃ 2.2-
The reinforced polyamide resin composition according to claim 1 or 2, wherein the composition is 5.5. 4. The reinforced polyamide resin composition according to claim 1, wherein (b) the inorganic filler is glass fiber, talc, or a nano-dispersed filler. 5. The reinforced polyamide resin composition according to claim 4, wherein the nano-dispersed filler is swelled montmorillonite, swellable fluoromica-based mineral, layered silicate or swellable mica. 6. The reinforced polyamide resin composition according to claim 1, wherein (c) the metal powder is an aluminum powder.