WO2003062320A1

WO2003062320A1 - Polyamide resin composition

Info

Publication number: WO2003062320A1
Application number: PCT/JP2003/000424
Authority: WO
Inventors: Tsutomu Tamura; Tomohide Nakagawa
Original assignee: Toyo Boseki Kabushiki Kaisha
Priority date: 2002-01-21
Filing date: 2003-01-20
Publication date: 2003-07-31
Also published as: JP4131369B2; JP2003213124A

Abstract

A polyamide resin composition comprising (A) a polyamide resin, (B) an inorganic reinforcement, (C) a thermoplastic resin other than the polyamide resin, and (D) a release agent, characterized in that the inorganic reinforcement (B) and the thermoplastic resin (C) are not in direct contact with each other and are independently evenly dispersed in the polyamide resin (A) serving as the continuous phase, the dispersed particles of the thermoplastic resin (C) have a diameter of about 2 µm or smaller, and the composition has an Izod impact strength of 150 J/m or higher. The polyamide resin composition can give a molding excellent in strength, rigidity, heat resistance, chemical resistance, and impact resistance and has satisfactory moldability.

Description

Specification

Polyamide resin composition

Technical field

The present invention relates to a polyamide-based resin composition, and more particularly, to a polyamide-based resin composition having good moldability that can provide a molded article having excellent strength, rigidity, elongation, impact resistance, and heat resistance.

Background art

Polyamide-based resin compositions have excellent mechanical, thermal, chemical, and electrical properties and are widely used in applications such as automotive parts, electric and electronic parts, industrial machine parts, and sports equipment parts. However, since the impact resistance at low temperatures is poor, it is well known that the impact resistance is improved by adding various impact improving resins.

(For example, Japanese Patent Application Laid-Open No. 60-238'360). Although this method improves the impact resistance, it has the disadvantage that strength, rigidity and heat resistance are significantly reduced. In order to remedy this drawback, there is a method of adding an inorganic reinforcing material. In other methods, the strength, rigidity and heat resistance are somewhat improved, but the effect of the improvement is not always sufficient.

The present inventors have found a method for solving the above problem by specifying the morphological structure of each component of the polyamide resin composition (Japanese Patent No. 2777762). However, when a mold release agent was added to meet the demand for further improving the moldability, there was a problem that the impact resistance was significantly reduced.

Disclosure of the invention

The present invention has been made in view of solving the above-mentioned newly generated problems, and has excellent strength, rigidity, heat resistance, chemical resistance, and excellent heat resistance from low to high temperatures of a polyamide resin. It is an object of the present invention to obtain an inexpensive polyamide resin molded product having impact properties and good moldability.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have finally completed the present invention.

That is, the present invention (1) A polyamide resin composition comprising (A) a polyamide resin, (B) an inorganic reinforcing material, (C) a thermoplastic resin other than the polyamide resin, and (D) a release agent, wherein the (B) ) The inorganic reinforcing material and (C) the thermoplastic resin are not directly in contact with each other, but are independently and uniformly dispersed in the continuous phase (A) polyamide resin, and (C) the thermoplastic resin A polyamide resin composition having a dispersed particle size of about 22 or less and an Izod impact strength of 150 J An or more.

② 100 parts by weight of a composition comprising (A) 93 to 30% by weight of a polyamide resin, (B) 5 to 65% by weight of an inorganic reinforcing material, and (C) 2 to 45% by weight of a thermoplastic resin. The polyamide resin composition according to claim 1, wherein the polyamide resin composition contains (D) a release agent in an amount of 0.3 to 5 parts by weight. It is.

Hereinafter, the present invention will be described specifically.

The polyamide resin (A) in the present invention has an acid amide bond (one C0NH—) in the molecule, and specifically includes ε-force prolactam, 6-aminocaproic acid, ω-enantholactam, —Aminopeptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, poly (pirididone), or other polymers or copolymers or prends, hexamethylenediamine, nonamethylenediamine, ゥPolymers, copolymers or copolymers obtained by polycondensation of diamines such as ndecamethylene diamine, dodecamethylene diamine, metaxylylene diamine and dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid and sebacic acid. Examples include renderings, but are not limited to these.

In the present invention, the polyamide resin preferably has a number average molecular weight of 7,000 to 30,000. If the number average molecular weight is less than 7,000, the toughness decreases, which is not preferable. If it is more than 30,000, the fluidity decreases, which is not preferable.

In the present invention, (Β) the inorganic reinforcing material includes glass fiber, carbon fiber, ceramics fiber, fibrous inorganic reinforcing material such as various whiskers, silica, alumina, talc, kaolin, quartz, powdered glass, myriki, Examples include powdery inorganic reinforcing materials such as graphite, but are not limited thereto. These inorganic reinforcements must be treated with a coupling agent to improve the adhesion to the polyamide resin. Is preferred.

As the coupling agent, any coupling agent such as a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent can be used, but a silane coupling agent is preferable, and an aminosilane compound is particularly preferable. A coupling agent and an epoxy silane coupling agent. The addition amount of the force coupling agent is at least 0.05 part by weight, preferably at least 0.1 part by weight, based on 100 parts by weight of the inorganic reinforcing material.

In the present invention, the blending amount of the inorganic reinforcing material (B) is 5 to 65% by weight, preferably 5 to 50% by weight. When the amount of the inorganic reinforcing material is less than 5% by weight, physical properties such as strength and rigidity of the polyamide resin composition of the present invention are not sufficient. On the other hand, if the amount of the inorganic reinforcing material exceeds 65% by weight, the molded product becomes brittle, and poor fluidity during molding and poor appearance of the molded product are not preferred.

In the present invention, (C) the thermoplastic resin other than the polyamide resin is a polyamide resin different from the above-mentioned polyamide, polyethylene (PE), polypropylene (PP), polymethylpentene (TPX), ethylene / propylene rubber (EPM ), Ethylene / propylene Z-gen rubber (EPDM), ethylene / α-olefin copolymer, ethylene / ethyl acrylate copolymer (ΕΕΑ), ethylene / methyl acrylate copolymer (ΕΜΑ), ethylene / methacrylic acid Polyolefin resin such as copolymer (EMM), ethylene Z vinyl acetate (EVA), AS resin, ABS resin, PS resin,

Examples thereof include, but are not limited to, polyester resins such as a block copolymer of prolactone, and polycapone resin. Two or more of these thermoplastic resins may be used in combination.

In the present invention, the (C) thermoplastic resin reacts with a polyamide resin. It preferably has a functional group, and the functional group is a polar group capable of reacting with a carboxyl group, an amino group, and an amide group in the main chain, which are terminal groups of the polyamide resin. Groups, an acid anhydride group, an epoxy group, an oxadrine group, an amino group, an isocyanate group, and the like. Among them, the acid anhydride group is most preferable because it has the highest reactivity with the polyamide resin.

The blending amount of the thermoplastic resin (C) in the present invention is 2 to 45% by weight, and preferably 5 to 40% by weight. If the amount is less than 2% by weight, the effect of improving the impact resistance is small.

Since the (D) release agent in the present invention has a great influence on the morphology of the polyamide resin composition in the present invention, the type of the release agent and the method of adding the same are extremely important. Can be divided into the following two groups.

(I) group; metal salts of higher fatty acids, specifically metal salts of stearic acid, lauric acid, naphthenic acid, montanic acid, etc., ie, metal salts of calcium, magnesium, barium, lithium, zinc, etc. . Among these metal salts of higher fatty acids, particularly preferred are magnesium stearate and calcium montanate.

(II) Group; specific release agents, such as:

(1) Silicon compounds having a 0H group in the side chain;

For example, a silicone compound represented by the following general formula (1) may be mentioned.

(CH ₃ ) 3 SiO

(E0) _m- (P0) _n - ² 0H

(In the general formula (1), Rl and R2 are alkyl groups, E0 is an ethylene oxide group, and P0 is Represents a propylene oxide group. )

(2) aliphatic amides;

Examples of the aliphatic amide include stearic acid amide, oleic acid amide, erucic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, and the like, but are not limited thereto. Absent. Of these, ethylene bis stearamide is particularly preferred.

(3) montanic acid ester or its partial peroxide;

Among montanic acid-based waxes, it is a partially modified montanic acid ester wax and montanic acid ester.

The mixing amount of these release agents is preferably from 0.03 to 5 parts per 100 parts by weight of a composition comprising (A) a polyamide resin, (B) an inorganic reinforcing material and (C) a thermoplastic resin having a functional group. Parts by weight, preferably 0.05 to 3 parts by weight. If the compounding amount is less than 0.03, the effect as a mold release agent of the molded article is small, and if it exceeds 5 parts by weight, contamination of a mold or the like may occur.

The morphological structure of the polyamide resin composition in the present invention is that (B) the inorganic reinforcing material and (C) the thermoplastic resin must be homogeneously dispersed in the polyamide resin substantially independently of each other. It is not preferable to use a morphology in which (B) the thermoplastic resin is directly surrounded by the (B) inorganic reinforcing material. In addition, (B) the inorganic reinforcement must be uniformly dispersed. On the other hand, the average dispersed particle size of (C) thermoplastic resin in (A) polyamide resin is 2 / m or less, preferably 1 im or less. If it exceeds 2 im, the distance between the particles increases, and the bending strength, bending rupture strain, and impact strength decrease, which is not preferable.

In the present invention, the Izod impact strength showing impact resistance is at least 150 J / m, preferably at least 200 J / m, and more preferably at least 200 J / m. In the present invention, in order to obtain a polyamide resin composition having the morphological structure as described above, a melt kneading production method by a special method is recommended. That is, (A) a polyamide resin and (C) a thermoplastic resin are melt-kneaded and uniformly finely dispersed in a melt-kneading machine, and then (B) an inorganic reinforcing material is further added and melt-dispersed to form a pellet. I do. Dry blending of these pellets with the (D) release agent (I) group is recommended. Alternatively, (A) a polyamide resin, (C) a thermoplastic resin having a functional group, and (D) a release agent (II) group are melt-kneaded and uniformly finely dispersed in a melt-kneading machine. It is recommended to add more inorganic reinforcement and disperse it. However, the polyamide-based resin composition of the present invention is not limited to the special production method described herein, and the polyamide-based resin composition and the polyamide-based resin composition of the present invention having a morphological structure thereof are not limited thereto. If available, other manufacturing methods can be used.

As the melt-kneading machine in the present invention, a single-screw extruder, a twin-screw extruder, a pressurized ader, a Banbury or the like can be used, and a particularly preferred melt-kneading apparatus is a vent type twin-screw extruder. In a vented twin-screw extruder, continuous production can be achieved by introducing the components of the (A), (C) and (D) release agents (II) group from the hopper and (B) component from the vent port. It is economical because it can be done. In addition, a twin screw extruder can obtain a strong shearing force by a combination of screw shapes, which enables efficient uniform kneading and fine dispersion.

The polyamide resin composition of the present invention may be used as a flame retardant, a phenolic antioxidant as a light or heat stabilizer, a phosphorus compound as a light or heat stabilizer, and a power to become a weather resistance improver. , An antistatic agent, a pigment, a dye, and the like may be added.

BEST MODE FOR CARRYING OUT THE INVENTION

Example

Next, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 to 5, Comparative Examples 1 to 5

(A) Polycabramide (NY-6, manufactured by Toyobo Co., Ltd., Toyobo Nylon T-840) was used as the polyamide resin.

(B) As an inorganic reinforcing material, glass fiber (CS03MA411 manufactured by Asahi Fiberglass Co., Ltd.) treated with a silane coupling agent was used.

(C) As a thermoplastic resin other than (A), maleic acid-modified ethylene / propylene Rubber (MAH modified EPR, MH-5020 manufactured by Mitsui Chemicals, Inc.) was used.

• (D) As a mold release agent, magnesium stearate (Nacalai Tesque reagent) of the (I) group, and a silicone compound having a 0H group in the side chain as a (II) group (Paintatto manufactured by Dow Corning Asia Co., Ltd.) Ethylene bisstearic acid amide (WE-183, manufactured by Kyoeisha Chemical Co., Ltd.), and a partial peroxide of montanic acid ester (wax 0P, manufactured by Hoechst) were used as the aliphatic amide.

The melt kneading machine was a 45 5 twin screw extruder with two vent ports (manufactured by Toshiba Machine Co., Ltd.), and the compound was manufactured by the following three manufacturing methods.

(1) Method; (A) polyamide resin, (C) thermoplastic resin, and (D) release agent are weighed in the amounts shown in Table 1, and are charged from the hopper of the extruder, and are discharged from the first vent port.

(B) Glass fibers were charged and melt-kneaded to produce pellets.

(2) Method: (A) Polyamide resin and (C) thermoplastic resin are charged from the hopper port of the extruder, (B) glass fiber is charged from the first vent port, and melt-kneaded to produce pellets. . Next, the pellet and the (D) release agent were dry-blended. Method (3): All the components (A), (B), (C) and (D) were simultaneously charged from the hopper of the extruder and melt-kneaded to produce pellets.

The cylinder temperature of the twin-screw extruder is 240 ° C to 290 ° C. The pellets thus obtained were molded into test pieces using an injection molding machine (IS80 manufactured by Toshiba Machine Co., Ltd.) in accordance with the ASTM standard, and subjected to physical property measurement. The molding conditions of the injection molding machine are a cylinder temperature of 280 ° C and a mold temperature of 80.

Flexural strength, flexural modulus and flexural strain were measured according to ASTM D-790, and Izod impact strength was measured according to ASTM D-256.

The morphology of the molded product was evaluated by observing the cross section of a test piece for bending measurement by the following method.

Observation / Measuring equipment: Field emission scanning electron microscope (Hitachi S-80G, acceleration voltage 6 KV)

Sample preparation method: Polishing method, Dyeing the sample with phosphotungstic acid (PTA).

Evaluation of morphology; Average dispersion particle size of MAH-modified EPR 1 or less: ◎, 1 Table 1 shows 〇 for over m and 2111 or less, and X for over 2 m. Table 1 also shows whether the glass fiber and MAH-modified EPR were not directly adhered but were substantially independently dispersed in the polyamide resin.

In Examples 1, 2 and 3, the MAH-modified EPR shows a dispersed particle size of 2 im or less. Glass fiber and MAH-modified EPR are dispersed independently of each other, and the surrounding area is a polyamide resin. Due to such a morphological structure, the strength properties have extremely excellent properties. On the other hand, in Comparative Example 1, dispersed particles of MAH-modified EPR having a large dispersed particle size of 10 nm or more exist, and the average particle size exceeds 22 xm. Glued. It can be seen that due to such a morphological structure, the physical properties, impact strength, bending fracture strain and bending strength are significantly reduced. In Comparative Example 2, since the release agent (D) belongs to the group (I), some interaction occurs between the magnesium stearate and the MAH-modified EPR during melt-kneading. It is thought that the impact strength and the bending fracture strain were reduced due to the large size of about 10 xm.

In Example 4, the same raw material components as in Comparative Example 2 were used. Since magnesium stearate was mixed by dry blending, the reaction between the MAH-modified EPR and the polyamide resin was not affected. Therefore, the morphological structure of the present invention is obtained, and excellent strength properties are obtained. In Example 5, as in Example 1, the morphological structure of the present invention and excellent strength properties were obtained. Comparative Example 3 has the same reason as Comparative Example 2, that is, since the production method is different from that of the Example, the dispersed particle size of the band-modified EPR is 5 m or more, and the impact strength and the bending fracture strain are low. On the other hand, Comparative Example 4 was a composition not containing glass fiber, and Comparative Example 5 was a composition not containing MAH-modified EPR, but none of them had balanced strength properties. In particular, it shows that the impact strength is greatly reduced and the toughness is poor. table 1

Industrial applicability

The molded article comprising the polyamide resin composition of the present invention is a resin composition having excellent strength, rigidity, heat resistance, chemical resistance, and excellent impact resistance from low to high temperatures, and having good moldability. Therefore, it can be widely used in fields where these characteristics are required. For example, it can be suitably used for exterior and interior parts of automobiles, specifically, rearview mirror parts, wheel caps, door handles, seat belt parts, and the like. In addition, it can be used in a wide range of applications, such as power tool parts, electric equipment parts, industrial machine parts, sports equipment parts, and other uses for construction and miscellaneous goods.

Claims

The scope of the claims

1. A polyamide resin composition containing (A) a polyamide resin, (B) an inorganic reinforcing material, (C) a thermoplastic resin other than the polyamide resin, and (D) a release agent, wherein the (B) ) The inorganic reinforcing material and (C) the thermoplastic resin are not in direct contact with each other, but are dispersed independently and uniformly in the continuous phase (A) polyamide resin, and (C) the thermoplastic resin A polyamide resin composition characterized by having a dispersed particle size of about 2 xm or less and an Izod impact strength of 150 J / m or more.

2. 100% by weight of a composition comprising (A) 93 to 30% by weight of a polyamide resin, (B) 5 to 65% by weight of an inorganic reinforcing material, and (C) 2 to 45% by weight of a thermoplastic resin other than the polyamide resin. The polyamide resin composition according to claim 1, wherein the polyamide resin composition contains (D) a release agent in an amount of 0.03 to 5 parts by weight based on parts.