JPS63162757A - Resin composition - Google Patents

Abstract

PURPOSE:To improve greatly the compatibility of polyamide resins with arom. polyether resins and to improve the chemical resistance, impact resistance and dimensional stability of the compsn., by increasing the concn. of the terminal amino groups of a polyamide resin. CONSTITUTION:This resin compsn. is obtd. by blending 5-95wt% polyamide resin (A) having a concn. ratio of terminal amino group to terminal carboxyl group not lower than 1.5 with 95-5wt% arom. polyether resin (B).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a polyamide resin with improved impact resistance, which is made of a polyamide resin having a concentration ratio of terminal amino groups to terminal carboxyl groups of 1.5 or more and an aromatic polyether resin. , relates to a resin composition with good chemical resistance and dimensional stability.

[Prior Art] Polyamide resins have drawbacks such as a decrease in mechanical properties due to moisture absorption, large dimensional changes, and a rapid decrease in rigidity at high temperatures above the glass transition temperature. In order to improve these drawbacks, glass fibers, carbon fibers, or various inorganic fillers are being filled. However, these methods have problems such as warpage occurring in molded pairs formed by various molding methods (for example, injection molding, extrusion molding, press molding, etc.) and reduction in impact resistance.

On the other hand, aromatic polyether resins have excellent thermal properties, maple-like properties, electrical properties, etc., as well as low hygroscopicity and good dimensional stability, and have become extremely popular in recent years. This resin is attracting attention. However, this resin has the drawback of poor chemical resistance, and improvements are desired.

In order to compensate for these mutual drawbacks, various blends of polyamide resins and aromatic polyether resins have been studied. (Japanese Patent Publication No. 59-41883) However, in such a simple blend of polyamide resin and aromatic polyethylene resin, since the polyamide resin and aromatic polyether resin are resins with different solubility parameters, There is no compatibilism between the resins, and there is poor adhesion between the two resins at the interface where different types of resins come into contact.Therefore, phase separation occurs during molding, and the mechanical properties of the molded product are poor, making it difficult to put into practical use. It is worthless. In order to avoid this compatibility problem, in JP-A-59-F18452, in a blend of polyamide resin and aromatic polyether resin, carboxyl group or
A method is described in which carboxylic acid anhydride groups are introduced as part of the substituents to improve the compatibility of both resins. In addition, in Japanese Patent Publication No. 60-11966, a compound with a specific structure was
A method has been proposed in which the compatibility of both resins is increased by adding it as a component.

[Problems to be Solved by the Invention] In the method of modifying an aromatic polyether resin with a carboxyl group or carboxylic acid anhydride, or in the method of adding a third component with a specific structure as a compatibilizer, it is difficult to solve the problem that a simple polyamide resin Although the compatibility of both resins is improved compared to a blend of polyester and aromatic polyether, it is still not practically satisfactory and improvements are desired.

In order to further improve the compatibility between polyamide resin and aromatic polyether resin, the inventors of the present invention have conducted intensive studies and found that by increasing the concentration of terminal amino groups of polyamide resin, the compatibility with aromatic polyether resin can be improved. It was discovered that the compatibility was significantly improved, and the present invention was completed.

[Means for solving the problem] That is, the present invention provides a polyamide resin (^) in which the concentration ratio of terminal amino groups to terminal carboxyl groups is 1.5 or more.
5 to 95 wt%, and aromatic polyether resin (B
) is a resin composition consisting of 95 to 5 wt%.

Hereinafter, the resin composition according to the present invention will be explained in detail.

The polyamide resin of the component (A) in the present invention refers to a polyamide resin having a terminal amino group ρ concentration ratio of 1.5 or more to the terminal carboxyl group (hereinafter, this polyamide resin may be referred to as a high-concentration amino-terminated polyamide). be.).

Specific examples of the polyamide resin of the present invention include nylon 6,
Nylon 11. Polylactams such as nylon 12, polyamides obtained from dicarboxylic acids and diamino such as nylon 66, nylon 61O, and nylon 612, nylon 8/8B, nylon 8/12, nylon 8/
EIIO, nylon 13/812, nylon 8/B
B/810, nylon 8/8B/812, nylon 6786/12. Examples include copolyamides such as nylon 8/BT (T: terephthalic acid component), and other known transparent nylons and polyamide elastomers.

These polyamides need to have a concentration ratio of terminal amino groups to terminal carboxyl groups of 1.5 or more, more preferably 2.0 or more. When the concentration ratio is less than 1.5, the compatibility between the polyamide resin and the aromatic polyether resin decreases, resulting in a decrease in mechanical properties such as impact resistance and bending fatigue resistance. ?
There is no particular restriction on the upper limit of the a ratio, and polyamides whose terminal groups are all amino groups can also be used6.
Regarding the molecular weight, it is preferable that the relative viscosity measured according to JIS-K8810 is 2.0 to 4.4.
Furthermore, the relative viscosity is more preferably 2.3 to 3.2.
．． If it is less than 0, the impact resistance of the polyamide resin itself,
If it exceeds 4.4, the bending fatigue resistance decreases and a satisfactory blend cannot be obtained. If it exceeds 4.4, the moldability decreases, which is not preferred in practice.

Polyamides having a high concentration of terminal amino groups can be produced by a method well known to those skilled in the art, which involves adding a chain transfer agent such as m-xylylene diamino, p-xylylene diamino, hexamethylene diamino, dodecamethylene diamino, etc. during polymerization. can be manufactured. Furthermore, monoamino such as stearyl amino and lauryl amino is added during polymerization to lower the concentration of terminal carboxyl groups, and there is no problem even if the ratio of the concentration of terminal amino groups to terminal carboxyl groups is 1.5 or more.

The aromatic polyether resin as component (B) in the present invention has the general formula R3R4 [where R1-R4 are the same or different alkyl groups, aryl groups, halogens, hydrogen, etc. residues, and n is 60 to 4
It is an integer of 00. ] It is expressed as .

Examples of aromatic polyether resins include poly(2,6
-Simethyl-1,4-phenylene)ether, poly(2
, B-diethyl-1,4-phenylene) ether, poly(2,6-diprobyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2- Methyl-6-broby-1.4
-phenylene) ether, poly(2-ethyl-6-brobyl-1.4-)dinidine) ether, 2,6-dimethylphenol/2,3.8-trimethylphenol copolymer, 2.6- Dimethylphenol/2,3.8-
) ethylphenol copolymer ffH', 2,6-dimethylphenol/2,3.8-) dimethylphenol copolymer, 2,6-diprobylphenol/2,3.8-
) dimethylphenol copolymer, graft copolymer obtained by grafting styrene onto poly(2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol/2,3.8-) dimethylphenol copolymer Examples include graft copolymers obtained by graft-polymerizing styrene onto a polymer.

In practicing the invention, other polymers (e.g., rubbery modified EPR, ionomer resins, etc.), glass fibers,
Fillers, flexibilizers, flame retardants, heat resistant agents, pigments, etc. used in polyamide resins well known to those skilled in the art, such as carbon fiber, talc, kaolin, wollastonite, silica, mica, and titanium oxide, may be added. .

In the resin composition components of the present invention, the content ratio of component (A) and component (B) is 5 to 95 wt% of component (A) and 9% of component CB).
If the content of component (A) is less than 5 wt%, the chemical resistance will significantly decrease, which is undesirable for practical use.
8) If the content of the component is less than 5 wt%, it is undesirable because the molded product will change in size due to moisture absorption and its mechanical properties will deteriorate.
The content ratio of component A) and component (B) is preferably 10 to 90 wt% of component (A).

(B) component is 90 to 10 wt%.

The resin composition of the present invention may be obtained by any method well known to those skilled in the art, such as a melt extruder, roll mixer, Banbury mixer, kneader, etc.

The resin composition according to the present invention obtained as described above can be used in a wide range of applications by taking advantage of its excellent physical properties.For example, by taking advantage of its mechanical properties and injection moldability, it can be used in cooling fans, radiator tanks, cylinder heads, oil Pans, valves, gears, wheel covers, brake tubes,
Suitable for use in automotive parts such as piping tubes (extrusion molding).

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

Examples 1-3 i) Preparation of pellets of 4#l fat composition Intrinsic viscosity measured at 25°C in chloroform is 0.48
(dl/g) of 2,8-dimethylphenol/2,3.
8-trimethylphenol copolymer (2,3,8-)dimethylphenol accounts for 5■O1%) and JI
Polyamide 6 having a relative viscosity of 2.6 and a concentration ratio of terminal amino groups to terminal carboxyl groups (hereinafter referred to as [NH4I/[COO]) of 9.8 as measured according to S-8810 was first used. Using a twin-screw melt extruder (manufactured by Japan Steel Works, Ltd., TEX-30) at the compounding ratio shown in the table,
The resin composition was melt-kneaded at a melting temperature of 260 to 300°C to produce pellets of the resin composition. Next, the pellets were dried in a vacuum dryer so that the moisture content became 0.03% or less.

ii) Measurement of compatibility, physical properties of pellets, etc. The compatibility, mechanical properties, and thermal properties of each of the above pellets were measured by the following measurement methods.

(a) Izotsu impact strength Measured in accordance with ASTM D-256.

(b) Heat distortion temperature (IIIT) Measured in accordance with ASTM D-648. The load was 18.58 Kg/cm2. (c) Bending fatigue A bending fatigue test was conducted at a bending angle of 80° using a No. 3 dumbbell piece (1.5 mm), and the number of bends at which cracks or breaks occurred was measured. .

(d) Evaluation of compatibility After etching the aromatic polyether resin on the cross section of the melt-kneaded pellet using chloroform solvent, SE of the cross section
An X-ray photograph (electron microscope) was taken to observe the sea-island structure of the polyamide resin and aromatic polyether resin, and the compatibility was evaluated.

×: Polyether islands with a diameter of 10 JL or more are scattered in the polyamide sea.

0: Polyether islands are large and scattered with about 5 wins.

0: There are no large polyether islands, and they are all smaller than one well.

Comparative Example 1 Relative viscosity measured according to JIS-6810 is 2.6
[NO3] / [000] Polyamide 6 with an old value of 0.7 and 2,6-dimethyphenol/2 as in Example 1.
．． 3.8-) Limethylphenol copolymer was melt-kneaded at the blending ratio shown in Table 1 to produce pellets, and the same evaluation as in Example 1 was conducted. In this example, when the kneaded material was extruded and cut into strings to form pellets, the moldability of the strings was poor and good pellets could not be obtained.

Example 4 Relative viscosity measured according to JIS-8810 is 2.3
Then, polyamide 66 with [NO3]/[C0OH] of 2.5 and 2.8-dimethylphenol/
2.3.8-) Limethylphenol copolymer was melt-kneaded at the blending ratio shown in Table 1, and the same evaluation as in Example 1 was performed.

Comparative Example 2 Relative viscosity measured according to JIS-' 6810G-
．． 9, [NO3]/[COO] polyamide 66 of 0.8 and 2.8-dimethyphenol as in Example 1/
2.3.8-) Limethylphenol copolymer was melt-kneaded at the blending ratio shown in Table 1, and the same evaluation as in Example 1 was performed. Note that, similar to Comparative Example 1, the moldability of the pellets was poor.

Example 5 Relative viscosity measured according to JIS-6810 is 2.8
So, [NH2]/[C00 old is 7.0 polyamide 12
and 2,6-dimethylphenol/2.
3.6-Trimethylphenol copolymer was melt-kneaded at the blending ratio shown in Table 1, and the same evaluation as in Example 1 was performed.

Comparative Example 3 Relative viscosity measured according to JIS-6810 is 2.6
So, [NHzl/[000 old is 0.8 nylon 12
and 2,6-dimethylphenol/2 as in Example 1,
The 3°6-dolimethylphenol copolymer was melt-kneaded at the blending ratio shown in Table 1 and evaluated in the same manner as in Example 1.

Note that, similar to Comparative Example 1, the moldability of the pellets was poor.

Example 6.7 Same composition as Examples 1 and 2 with average molecular weight 2.8000
The same evaluation as in Example 1 was performed by adding 3 wt % of polybutadiene in which both end groups of were modified to carboxyl groups based on the total amount of the nylon resin and the aromatic polyether resin, melt-kneading the mixture, and performing the same evaluation as in Example 1.

Example 8 A modified polybutadiene having the same composition as in Example 6 in which both end groups were modified to epoxy groups was melt-kneaded and evaluated in the same manner as in Example 1.

Example 9 Using the combination of Example 8, the blending ratio of polyamide resin/aromatic polyether resin was 476, and polybutadiene with both terminal groups modified to epoxy groups was added to the total amount of polyamide resin and aromatic polyether resin. The same evaluation as in Example 1 was performed by adding 5 wt% of the mixture and melt-kneading it.

Example 1O Polyamide 66, which had the same composition as in Example 4 and was used in Example 4, was melt-kneaded and evaluated in the same manner as in Example 1.

Comparative Example 4 Polyamide 6, which had the same composition as in Example 6 and was used in Comparative Example 1, was melt-kneaded and evaluated in the same manner as in Example 1. Note that, similar to Comparative Example 1, the moldability of the pellets was poor.

The above results are summarized in Table 1.

[Effects of the invention] The above resin composition can greatly improve compatibility with aromatic polyether resins compared to commonly used unmodified polyamide resins, eliminate resin phase separation, and improve impact resistance and Mechanical properties such as bending fatigue resistance are improved, and the drawbacks of both resins, such as dimensional change due to moisture absorption, warpage, and chemical resistance, are improved.

Procedural amendment March 26, 1988

Claims (1)

[Claims] (1) Polyamide resin (A) with a concentration ratio of terminal amino groups to terminal carboxyl groups of 1.5 or more 5 to 95 wt%
, and aromatic polyether resin (B) 95-5wt
A resin composition consisting of %.