JP2001049117A - Polyamide based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide based resin composition excellent in dimensional stability in water absorbing state by including an intercalation compound of a layered silicate prepared by intercalating a triazine derivative having positive charge, in a polyamide resin and a polyphenylene ether based resin. SOLUTION: This polyamide based resin composition comprises 100 pts.wt. of a resin comprising (A) 10-90 wt.% of a polyamide resin and (B) 90-10 wt.% of a polyphonylene ether based resin, and (C) 0.5-30 pts.wt. of an intercalation compound of a layered silicate prepared by intercalating a triazine derivative having one or more positive charged groups. The preferable intercalation compound of silicate prepared by intercalating triazine exhibits cation exchanging capacity of 0.1-10 equivalent to that of a laminar silicate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition having excellent dimensional stability when absorbing water.

[0002]

2. Description of the Related Art Polyamide resins are used as engineering plastics having excellent heat resistance and mechanical strength in various fields such as various industrial parts. But,
Polyamide resins have high water absorption, and thus have disadvantages such as a decrease in strength due to water absorption and a change in the dimensions of molded articles.

[0003] To improve this, a method of adding a thermoplastic resin having low water absorption has been proposed. Among them, it is particularly known that when a polyphenylene ether-based resin is added, a resin composition having excellent fluidity, heat resistance, rigidity and the like can be obtained (JP-A-56-16525, JP-A-59-16559). -66452, JP-A-56-26
913, JP-A-63-10656, etc.). Japanese Patent Application Laid-Open No. 2-166157 discloses a polyamide resin composition which further comprises a layered silicate and has excellent heat resistance and impact resistance.

[0004]

However, a composition to which a polyphenylene ether-based resin is added can be used for parts requiring high dimensional accuracy, such as precision parts and large molded articles.
Since the dimensional stability at the time of water absorption is not sufficient, there has been a problem that applications are limited. The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a polyamide resin composition having excellent dimensional stability when absorbing water.

[0005]

Means for Solving the Problems The present inventors have intensively studied a polyamide resin composition which does not impair the excellent characteristics of the polyamide resin and the polyphenylene ether resin, and which has remarkably improved dimensional stability upon water absorption. As a result, it has been found that the above-mentioned problem can be solved by a polyamide-based resin composition containing a layered silicate in which a positively charged triazine-based compound derivative is introduced between the polyamide resin and the polyphenylene ether-based resin, and the present invention has been completed. It has been reached.

That is, the present invention relates to (A) 100 parts by weight of a resin component comprising 10 to 90% by weight of a polyamide resin and (B) 90 to 10% by weight of a polyphenylene ether resin, and (C) a triazine having a positive charge. Triazine phyllosilicates having a compound derivative between layers
An object of the present invention is to provide a polyamide resin composition comprising 0.3 to 30 parts by weight and having improved dimensional stability upon water absorption.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide resin (A) in the present invention is generally a high molecular compound having an acid amide bond (-CONH-) as a repeating unit, and is not particularly limited. , Polyamides from lactams such as polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 6
12. Polyamides from dicarboxylic acids and diamines such as polyamide 46, polyamide 6-66, polyamide 6-
610 and the like, polyamide 6T, polyamide 6I, polyamide 6T / 6I, polyamide MXD
Semiaromatics selected from aromatic dicarboxylic acids such as terephthalic acid (T) and isophthalic acid (I) and aliphatic diamines, or aromatic diamines such as m-xylylenediamine (MXD) and aliphatic dicarboxylic acids. Group polyamides and the like. These polyamide resins may be used alone or in combination of two or more.

The (B) polyphenylene ether-based resin in the present invention is not particularly limited, and is a polymer in which benzene ring residues are linked via an ether bond and can be heated and melted. These are produced from phenols or reactive derivatives thereof by a known method, for example, oxidative coupling polymerization using oxygen or an oxygen-containing gas using an oxidative coupling catalyst. Representative phenols include phenol, o-cresol, 2,6-xylenol, 2,5-xylenol,
And methylphenols such as 2,3,6-trimethylphenol. These phenols may be used alone or
It may be used as a combination of more than one kind. The most common polyphenylene ether resins are poly (2,
Examples thereof include 6-dimethyl-1,4-phenylene) ether and a copolymer having the main structure, but a mixture containing two or more kinds of polyphenylene ether-based resins can also be used. In order to increase the compatibility between the polyamide resin and the polyphenylene ether-based resin, it is preferable to modify the polyphenylene ether-based resin. Specific examples include incorporating a compound having a functional group reactive with the polyamide resin into the molecule, and graft-polymerizing a modifier such as an unsaturated carboxylic acid or a derivative thereof.

The composition ratio of the component (A) in the total resin component of the components (A) and (B) is in the range of 10 to 90% by weight, more preferably 30 to 80% by weight. When the composition ratio of the component (A) is less than 10% by weight, the moldability decreases, while when it exceeds 90% by weight, the dimensional change upon water absorption is undesirably large.

The (C) triazine-modified layered silicate of the present invention is obtained from a layered silicate and a triazine compound derivative, and the triazine compound derivative is obtained by subjecting a triazine compound and a Lewis acid compound to an acid-base reaction. Can be

[0011] Layered silicates are rich in changes such as chemical composition and crystal structure, and there is no established classification and nomenclature. The feature of the layered silicate mentioned here is a layered crystal, which belongs to phyllosilicate in mineralogy. Particularly, there is a 2: 1 type phyllosilicate composed of two tetrahedral layers and one octahedral layer, and a 1: 1 type phyllosilicate composed of one tetrahedral layer and one octahedral layer. Typical minerals of type phyllosilicate include smectite, vermiculite,
There are mica and chlorite, and 1: 1 phyllosilicate includes kaolin, serpentine and the like. The smectite group includes saponite, hectorite, sauconite,
There are montmorillonite, beidellite, nontronite, stephensite, etc., the vermiculite group includes trioctahedral vermiculite, dioctahedral vermiculite, etc. Paragonite, chlorite, margarite, teniolite,
And a composition such as tetrasilicic mica. These phyllosilicates may be produced naturally or synthesized by a hydrothermal method, a melting method, a solid phase method, or the like.

The triazine compound refers to a compound having a 6-membered ring containing three nitrogen atoms, preferably 1,3,5
-Triazine compounds, specifically, melamines such as melamine, N-ethylenemelamine, N, N ′, N ″ -triphenylmelamine, cyanuric acid, isocyanuric acid, trimethylcyanurate, tri (n -Propyl) cyanurate, tris (n-propyl) isocyanurate, diethylcyanurate, N, N'-diethylisocyanurate, methylcyanurate, cyanuric acid such as methylisocyanurate, equimolar reaction product of melamine and cyanuric acid And melamine cyanurate consisting of The melamine cyanurate compound is, for example, a mixture of an aqueous solution of melamine and an aqueous solution of cyanuric acid, about 90 to 90
It can be obtained by performing a stirring reaction at a temperature of 100 ° C.

The Lewis acid compound is an electron pair acceptor,
For example, hydrogen acids such as hydrochloric acid and hydrogen sulfide, sulfuric acid, nitric acid, oxo acids such as acetic acid and phosphoric acid, thio acids such as ethyl xanthogenic acid,
Examples thereof include alkyl halides and acid halides.

As a method for obtaining a triazine derivative having a positive charge in the present invention, a method in which a triazine compound which is a base is dissolved in water or alcohol, a Lewis acid is added, and the mixture is stirred to cause an acid-base reaction. Is exemplified. The amount of the Lewis acid to be added may be triazine compound 1
It is usually 0.01 to 3 mol, and 0.1 to 0.1 mol.
Two moles are more preferred. The produced triazine-based compound derivative can be used as it is in a solution state, but may be taken out and used. Alternatively, a commercially available product can be used as it is or after being dissolved in a solvent such as water.

The method for mixing the layered silicate and the triazine compound derivative to obtain the triazine-modified layered silicate of the present invention is not particularly limited. For example, a method in which both the layered silicate and the triazine-based compound derivative are contacted via a medium having an affinity, a method in which the layered silicate and the triazine-based compound derivative are directly mixed and contacted without using a medium, and the like are exemplified. The method of contacting via a medium is exemplified by a method in which each is dispersed in a solvent, homogenized, mixed with stirring, and the solvent is removed. As a method of directly mixing, a method in which both are simultaneously placed in a ball mill, a mortar, or the like and pulverized together is used.

The amount of the triazine-based compound derivative in the triazine-modified layered silicate is 0.1 to 10 equivalents with respect to the cation exchange capacity (hereinafter referred to as CEC) of the layered silicate.
Preferably 0.3 to 5 equivalents, more preferably 0.5 to
It is in the range of 2.0 equivalents. If the amount of the triazine-based compound derivative, which is an organic cation, is less than 0.1 equivalent, the dispersion of the interlayer compound in the resin composition decreases, and sufficient mechanical properties and dimensional stability upon water absorption cannot be exhibited. 1
If the equivalent is 0 or more, the amount of the positively charged organic compound becomes excessive relative to the amount of the inorganic component, which impairs the mechanical strength and heat resistance of the composite resin material, and may cause mold deposit during molding, which is not preferable.

Since the CEC of the layered silicate varies depending on the type, production place and composition of the layered silicate, it is necessary to measure it in advance. As the measurement of CEC, for example,
Column infiltration method (see: Clay Handbook, 2nd edition, edited by The Clay Society of Japan, pp. 576-577, published by Techniquedo),
Methylene blue adsorption method (Japan Bentonite Industry Association Standard Test Method, JBAS-107-91) and the like.

The confirmation of the insertion of the triazine compound-based derivative into the layered silicate is performed by measuring the triazine-modified layered silicate by powder X-ray diffraction (XRD) and thermogravimetry (TG / DT).
A) can be estimated. By inserting the triazine compound-based derivative, the bottom surface distance d (00
1) increases, and its content can be known from the weight loss when heated.

The amount of the triazine-modified layered silicate in the polyamide resin composition of the present invention is 0.3 to 30 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 100 parts by weight of the resin component. Is in the range of 1 to 10 parts by weight. If the amount is less than 0.1 part by weight, the mechanical strength and the dimensional stability at the time of water absorption are insufficient, and if it exceeds 30 parts by weight, the impact resistance is reduced and the moldability is impaired.

In order to further increase the compatibility between the polyamide resin and the polyphenylene ether resin, an unsaturated carboxylic acid and a peroxide may be added at the time of mixing with the polyamide resin by kneading them at the same time. In order to improve the properties, a thermoplastic elastomer may be blended, or a thermoplastic resin for improving various properties may be blended.

Further, additives commonly used in the art, for example, antioxidants, ultraviolet absorbers, flame retardants, lubricants, antistatic agents, coloring agents, reinforcing agents, etc. are added to the extent that the effects of the present invention are not impaired. Is also good.

The method of mixing the components (A) to (C) of the present invention is not particularly limited, and examples thereof include a continuous mixer, a Banbury mixer, a roll, a single screw extruder, a twin screw extruder, and a tandem type. A method in which the resin component and the triazine-modified layered silicate are melt-kneaded in a melt-kneading apparatus such as an extruder or the like is used.

[0023]

The present invention will now be described with reference to the following examples.
It is not limited to these examples. The dimensional change was measured by measuring the dimensional change after dipping No. 1 dumbbell (ASTM D638) in water at 23 ° C for 7 days, and the average value was%.
It was expressed by.

As a polyamide resin, polyamide 66 (hereinafter referred to as “PA-1”) having a relative viscosity of 2.7 (measured at a temperature of 25 ° C. of a 1% by weight polymer solution in 98% by weight sulfuric acid).
And polyamide 6 having a relative viscosity of 2.7 (hereinafter referred to as “PA-2”). As the polyphenylene ether-based resin, poly (2,6-dimethyl-1,4
-Phenylene) ether (intrinsic viscosity [μ] of a 0.6 g / dl chloroform solution at 25 ° C. = 0.47 (d
1 / g)) A modified polyphenylene ether resin (hereinafter, referred to as “melt-kneaded”) obtained by melt-kneading 0.8 part by weight of maleic anhydride and 1.0 part by weight of benzoyl peroxide having a purity of 30% based on 100 parts by weight "PPE") was used.

The triazine-modified layered silicate was prepared by the following method. SC-1: 200 g of synthetic sodium tetrasilicic mica (ion exchange capacity: 107 meq / 100 g “Somasif ME-100” manufactured by Corp Chemical Co., Ltd.) was distilled water 400
Mix in 0 cc and swell well. This dispersion is
After heating to 0 ° C., an aqueous solution of melamine hydrochloride at 60 ° C. was added in an amount of 1.0 equivalent to the ion exchange capacity of the layered silicate, and the mixture was sufficiently stirred to perform an ion exchange reaction. This suspension was filtered, washed and filtered repeatedly, dried and pulverized to obtain a triazine-modified layered silicate. The resulting triazine-modified layered silicate had a bottom surface interval of 1.3 nm and a cyanuric acid derivative content of 10% by weight. SC-2: A triazine-modified layered silicate was prepared from 200 g of synthetic sodium tetrasilicic mica, cyanuric acid (160 mmol), and hydrochloric acid (160 mmol) in the same manner as described above. The bottom spacing of the obtained triazine-modified layered silicate was 1.3 nm, and the content of the cyanuric acid derivative was 15% by weight.

Examples 1 to 6 and Comparative Examples 1 to 3 Each component was blended in the composition shown in Table 1 and melt-kneaded at 270 ° C. in a twin-screw extruder to prepare pellets. Each of the obtained pellets was molded into a No. 1 dumbbell using an injection molding machine, and the dimensional change was measured. Table 1 shows the results.

[0027]

[Table 1]

[0028]

Industrial Applicability The polyamide resin composition of the present invention has excellent dimensional stability upon water absorption, and is therefore suitably used for industrial parts that require dimensional accuracy, such as precision parts and large molded products. Useful.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junichi Nakamura 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory (72) Inventor Masayuki Noguchi Kawasaki-ku, Kawasaki-shi, Kanagawa 3-2 Chidoricho Showa Denko KK Kawasaki Laboratory, Research Institute (72) Inventor Ao Ebata 3-2 Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory F-term ( Reference) 4J002 CH07X CL01W CL03W CL05W DJ006 EU186 EU196

Claims (2)

[Claims] (1) 10 to 90% by weight of a polyamide resin (A)
And (B) polyphenylene ether resin 90 to 10
100% by weight of a resin component consisting of
A polyamide resin composition comprising 0.3 to 30 parts by weight of a triazine layered silicate having a triazine derivative having a positive charge between layers. 2. The polyamide resin composition according to claim 1, wherein the triazine-modified layered silicate has between 0.1 and 10 equivalents of a triazine-based compound derivative relative to the cation exchange capacity of the layered silicate. .