JPH02167364A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition improved in impact resistance, etc., by blending a polyphenylene oxide-based resin with specific amounts of a polyamide resin, etc., having terminal amino groups in a larger amount than that of terminal carboxyl groups. CONSTITUTION:A resin composition obtained by blending 100 pts.wt. total amount of (A) 30-70 pts.wt. polyphenylene oxide-based resin and (B) 70-30 pts.wt. polyamide resin having >=1.01, preferably >=1.3 equiv. ratio of terminal amino groups to terminal carboxyl groups with (C) 0-20 pts.wt. rubber-like substance (e.g. natural rubber or butadiene polymer).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition containing a polyphenylene oxide resin and a polyamide resin.

[Prior Art and its Problems] Polyphenylene oxide is useful as a resin for molding materials because of its strong mechanical and electrical properties, but its oil resistance is insufficient. In order to improve this point, it is known to mix polyphenylene oxide and polyamide with good body properties (for example, JP-A-56-16
525). However, since polyphenylene oxide and polyamide have poor compatibility with each other, the properties originally possessed by both resins, such as good mechanical properties, are not exhibited in the amount of molding made from a resin composition in which they are mixed. In particular, there is a problem of poor impact resistance. In order to solve this problem, a method is known in which polyphenylene oxide and polyamide are melt-kneaded with unsaturated carboxylic acid, etc. (Japanese Patent Laid-Open No. 56-26913). It is also known to add aliphatic polycarboxylic acids etc.
195>.

[Structure of the Invention] In a resin composition containing a polyphenylene oxide resin, a polyamide resin, and optionally a rubber-like substance, the present inventor has developed a polyamide resin in which the amount of terminal amino groups in the polyamide is larger than the amount of terminal carboxyl groups. The present invention was completed based on the discovery that the mechanical strength, such as impact resistance, of a molded mass made from a resin composition can be considerably improved by using the resin composition.

That is, the present invention comprises (A) 30 to 70 parts by weight of a polyphenylene oxide resin (B) 70 to 30 parts by weight of a polyamide resin in which the amount of terminal amino groups is larger than that of the terminal carboxyl group (C) The above component (A) and 0 to 20 parts by weight per 100 parts by weight of (B)
A resin composition containing parts by weight of a rubber-like material.

A major feature of the present invention is the use of a polyamide in which the amount of terminal amino groups is greater than the amount of terminal carboxyl groups. The use of such polyamide dramatically improves the impact resistance of the molded amount, as will be described later.

Here, the polyphenylene oxide resin is known per se, and for example, the general formula [wherein R1, R2, R3 and R4 are hydrogen, halogen,
Indicates a monovalent substituent selected from alkyl groups, alkoxy groups, haloalkyl groups having at least two carbon atoms between the halogen atom and the phenyl ring, and haloalkoxy groups that do not contain a tertiary α-carbon. , n is an integer representing the degree of polymerization] is a general term for polymers represented by the above general formula, and is a copolymer that is a combination of two or more of the polymers represented by the above general formula. It may be. In a preferred embodiment, R1 and R2 are alkyl groups having 1 to 4 carbon atoms, and R3, R
4 is hydrogen or an alkyl group having 1 to 4 carbon atoms. For example, poly(2,6-dimethyl-1,4-phenylene>ether, poly(2,6-diethyl-1,4-phenylene)ether, poly(2-methyl-6-ethyl-1,
4-phenylene) ether, poly(2-methyl-6-broby-1,4-phenylene) ether, poly(2,F
dipropyl-1,4-phenylene) ether, poly(2
-ethyl-6-brobyl-1,4-phenylene>ether and the like.

A particularly preferred polyphenylene ether resin is poly(2,
6-dimethyl-1,4-phenylene) ether.

Examples of the polyphenylene ether copolymer include copolymers containing a portion of alkyl trisubstituted phenol, such as 2,3,6-dolimethylphenol, in the polyphenylene ether repeating unit. Alternatively, a copolymer in which a styrene compound is grafted onto these polyphenylene ethers may be used. The styrene-based compound-grafted polyphenylene ether is a copolymer obtained by graft-polymerizing a styrene-based compound such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene, etc. to the above-mentioned polyphenylene ether.

Polyamide resin itself is known, such as nylon-4, nylon-6, nylon-6,6, nylon-
12, nylon-6,10, etc., but are not limited to these. What is essential in the present invention is that the amount of terminal amino groups in the polyamide is greater than the amount of terminal carboxyl groups. Such a polyamide can be obtained by adding an extra compound having a group that reacts with a carboxyl group, such as diamino, during the polymerization of the polyamide. Alternatively, after polymerization of polyamide,
For example, this can also be achieved by reacting with a compound having a group that reacts with a carboxyl group.

In the present invention, it is important that the equivalent ratio of terminal amino groups to terminal carboxyl groups (hereinafter referred to as terminal group ratio) of the polyamide is greater than 1. As a result, surprisingly, a resin composition with significantly improved mechanical strength and a molded article with a relatively excellent surface appearance can be produced.

Usually, the polyamide resin has a terminal Da group ratio of 1 or less. In polyamides for index molding, a terminal capping agent is added to the polymerization component in order to appropriately control the melt viscosity, but the terminal group ratio of such polyamides is less than 1. When a polyamide with an end group ratio of more than 1 is used according to the present invention, the mechanical strength of the molded article is dramatically improved compared to a case where a polyamide with an end group ratio of 1 or less is used. It is surprising that such a significant difference occurs due to the difference in the end group ratio of polyamide. The end group ratio is
It is 1.01 or more, preferably 1.1 or more, more preferably 1.3 or more.

In the present invention, (^) polyphenylene oxide-based resin and (B) polyamide resin in which the amount of terminal amino groups is larger than the amount of terminal carboxyl groups are in the range of 30 to 70 parts by weight and 70 to 30 parts by weight, respectively. It is blended with.

If the amount of component (B) is more than this, it is difficult to achieve the desired properties of component (A) itself, and on the other hand, if it is less than this, it is difficult to achieve the improvement in oil resistance that is the purpose of adding component (B).

The resin composition of the present invention may contain a rubber-like substance (C), if necessary, in order to improve the impact strength of the molded article (1+i).

Rubber-like materials are natural and synthetic polymeric materials that are elastic at room temperature. Specific examples include natural rubber, butadiene polymer, butadiene-styrene copolymer (random copolymer, block copolymer, graft copolymer, etc.)
All included. ), isoprene polymer, chlorobutadiene polymer, butadiene-acrylonitrile copolymer, isobutylene polymer, isobutylene-butadiene copolymer, isobutylene-isoprene copolymer, acrylic acid ester polymer, ethylene-propylene copolymer, Examples include ethylene-propylene-diene copolymer, thiocol rubber, polysulfide rubber, polyurethane rubber, polyether rubber (eg, polypropylene oxide, etc.), and chlororeohydrin rubber.

These rubber-like materials can be produced by any method of preparation (e.g. emulsion polymerization, solution polymerization), by any treatment (e.g. peroxides,
Trialkylaluminum, lithium halide, nickel-based catalysts) may also be used. Further, rubber particles having various degrees of crosslinking, microstructures in various proportions (for example, cis structure, trans structure, vinyl group, etc.), or rubber particles having various average particle diameters may also be used.

Further, any of various copolymers such as random copolymers, block copolymers, and graft copolymers can be used as the rubber-like material of the present invention. Furthermore,
In making these rubber-like substances, other olefins,
Copolymerization with monomers such as dienes, aromatic vinyl compounds, acrylic acid, acrylic esters, and methacrylic esters is also possible. Any method such as random copolymerization, block copolymerization, graft copolymerization, etc. can be used for their copolymerization. Specific examples of these monomers include:
For example, ethylene, propylene, styrene, chlorostyrene, α-methylstyrene, butadiene, isoprene,
Examples include chlorobutadiene, butene, isobutylene, methyl acrylate, acrylic acid, ethyl acrylate, butyl acrylate, methyl methacrylate, and acrylonitrile. Furthermore, partially modified rubber-like substances can also be used, such as hydroxy or carboxy-
Examples include terminal-modified polybutadiene, partially hydrogenated styrene-butadiene block copolymer, and the like.

Rubber-like substance (C) consists of components (A) and (B) in total of 10
0 to 20 parts by weight are added to 0 parts by weight. This component (C) is added to improve the impact resistance of the molded article. Compositions that do not contain this component (C) are also possible. In the present invention, in molded articles made from compositions that do not contain component (C), the improvement in impact resistance is relatively small, but the improvement in surface appearance is remarkable.

The above-mentioned components (A) to (C) can be blended in any order by a conventional method, heated and melted, and then injection-melted.

The compositions of the invention may further include other crushing ingredients, such as glass I.
Fillers such as carbon fiber, carbon fiber, carbon black, silica, titanium dioxide, plasticizers, flame retardants, pigments, dyes, etc. can be added.

The present invention will be explained below using examples.

[Example] Example 1, Comparative Example 1. ~2 Poly(2,6-dimethyl-1,4-phenylene)ether was used as component (A). Nylon-6 having various end group ratios was used as component (B) polyamide.

The polyamide used in the example had 8.4 XIO'mol/
Polyamide with terminal amino groups of g and terminal carboxyl groups of 1.8 x 10'mol/9 (molecular weight 13.000)
and 4.6 XIO' mol/g of terminal amino groups, 7, O
It was made by blending a polyamide (molecule f! 13,000>) with terminal carboxyl groups of XIO' mol/g.

Component (C) is SBS (styrene-butadiene-
A styrene block copolymer (Califlex TRll0I manufactured by Shell) was used.

First, pellets were made by extruding a blend of the above components at a temperature of 290°C using a twin screw extruder equipped with a vacuum vent. A molded article was made from the pellets using an injection molding machine set at a cylinder temperature of 280°C, an injection pressure of 1.200 K'j/cri, and a mold temperature of 80'C.

To evaluate the molded product, an Izot impact test (with a 1/8 inch notch) was conducted in accordance with JIS K 7110. The appearance of the molded product was observed with the naked eye.

Table 1 shows the results of examples in which the end group ratio of polyamide was varied.
Shown below.

In the table, PPO refers to component (A>) and PA refers to component (B).

From Table 1, the terminal group equivalent ratio of polyamide (N 1-12/
It can be seen that when COO) is larger than 1, the impact resistance is significantly improved. The surface appearance of the Example was also clearly better than that of the Comparative Example.

Comparative Example 3 Since the polyamide used above has a lower viscosity than polyphenylene oxide, the dispersion of polyphenylene oxide in the polyamide is inherently poor.

Next, experiments were conducted in which the molecular weight of the polyamide was increased, but the end group equivalent ratio remained below 1. The properties of the nylon-6 used are as follows.

Molecular weight: 30.000 End group equivalent ratio: 0.94 A molded article was produced in the same manner as in Example 1 except for the following. The Izod impact value was only 2.3 Kl·cm/cm.

As a conclusion from the above, if the terminal group equivalent ratio of the polyamide remains smaller than 1 as before, the impact resistance cannot be improved even if the dispersion of polyphenylene oxide is improved by setting the molecular weight of the polyamide high. On the other hand, when a polyamide with a terminal @ group equivalent ratio of more than 1 is used, even if the polyamide does not have a large molecular weight or a low viscosity, it has excellent impact resistance and a relatively good surface appearance. The amount of molding can be obtained.

Claims (1)

[Claims] 1. (A) Polyphenylene oxide resin 30-70
Part by weight (B) 70 to 30 parts by weight of a polyamide resin in which the amount of terminal amino groups is greater than the amount of terminal carboxyl groups (C) 0 to 20 parts by weight of rubber based on a total of 100 parts by weight of the above components (A) and (B) A resin composition containing a similar substance. 2. The resin composition according to claim 1, wherein component (B) has an equivalent ratio of terminal amino groups to terminal carboxyl groups of 1.01 or more. 3. The resin composition according to claim 2, wherein the equivalent ratio of terminal amino groups to terminal carboxyl groups in component (B) is 1.1 or more. 4. The resin composition according to claim 3, wherein component (B) has an equivalent ratio of terminal amino groups to terminal carboxyl groups of 1.3 or more.