JPH02261861A - Impact-resistant resin composition - Google Patents

Abstract

PURPOSE:To prepare a resin compsn. wherein the degradation of impact strength is improved by compounding a polyamide, a polyphenylene ether, a rubberlike material, and a specified amt. of an inorg filler in a specified manner. CONSTITUTION:A resin compsn. comprising a polyamide, a polyphenylene ether, a rubberlike material, and an inorg. filler, wherein the polyamide forms a continuous phase, the polyphenylene ether disperses as particles with a mean diameter of 0.1 to 10mum in the continuous polyamide phase, the rubberlike material is contained in the dispersed polyphenylene ether particles, and the amt. of the filler dispersed in the polyphenylene ether and rubberlike material is larger than the amt. of the filler dispersed in the polyamide. Such dispersion of the filler is obtd. by mixing the filler first with the rubberlike material to give a rubber compd., and then mixing the compd. with the polyamide and the polyphenylene ether.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition comprising a polyamide, a polyphenylene ether and a rubbery substance.

[Conventional technology]

Polyamide is widely used as a molding resin and has excellent mechanical strength, solvent resistance, heat resistance, moldability, etc.
It is inferior in terms of dimensional stability and changes in physical properties due to moisture absorption.

Polyphenylene ether has excellent dimensional stability, electrical properties,
Although it is known as an engineering resin with excellent heat resistance and water resistance, it has problems in terms of solvent resistance and moldability.

Therefore, by using a mixture of both resins, the advantages of both resins can be taken advantage of, and the disadvantages of each other can be compensated for (many studies have been carried out).Since polyamide and polyphenylene ether are inherently poor in compatibility, styrene is used as a compatibilizer. A composition has been proposed in which a copolymer of an α,β-unsaturated dicarboxylic acid and a rubber-like substance is added as an impact modifier (Japanese Patent Publication No. 59-33614).

Furthermore, a method in which maleic anhydride is added as a compatibilizer and melt-kneaded (Japanese Patent Publication No. 80-11966) and a composition in which a rubbery substance is further added (Japanese Patent Application Laid-Open No. 56-49753) have been proposed.

On the other hand, although mechanical strength is improved by adding a compatibilizer in this way, the dispersion of the openings on both sides becomes too fine, resulting in insufficient impact strength and a decrease in molding fluidity. Compositions have been proposed that define the dispersion state of the resin. That is, polyphenylene ether is present in the polyamide from 2 to
A composition is known in which a rubber-like substance is microdispersed in polyphenylene ether as particles of 10 μm (Japanese Patent Application Laid-Open No. 151456/1983). or,
A multiphase structure has been proposed in which a polyphenylene ether with a specific viscosity is dispersed in a polyamide matrix phase with a specific viscosity, and a diene block copolymer is dispersed in the polyphenylene ether (Japanese Patent Application Laid-Open No. 1983-1999). 27325
Publication No. 4).

On the other hand, it is well known that by blending various inorganic fillers with thermoplastic resins, rigidity, dimensional stability, heat resistance, coloring, etc. can be increased.

However, it has been found that when an inorganic filler is blended and melt-kneaded in addition to the polyamide and polyphenylene ether (or even rubber-like substances) as described above, the physical properties of the molded product, especially the impact resistance, are significantly reduced. . This is thought to be because the inorganic filler hinders the development of the specific dispersed structure as described above.

[Problem to be solved by the invention]

An object of the present invention is to provide a resin composition that solves the problem of reduced impact resistance when an inorganic filler is blended into a resin composition composed of polyamide, polyphenylene ether, and a rubbery substance.

[Means to solve the problem]

The above problem is solved by dispersing the majority, preferably most, of the inorganic filler in the polyphenylene ether and the rubbery material, such that the polyamide, the polyphenylene ether and the rubbery material are in a specific dispersed structure. It turns out.

That is, the present invention provides polyamide, polyphenylene ether,
In a resin composition containing a rubbery substance and an inorganic filler,
Polyamide forms a continuous phase, polyphenylene ether is dispersed in the polyamide with an average particle size of 0.1 to 10μ, a rubbery substance is mainly contained in the polyphenylene ether dispersed phase, and polyphenylene ether and the rubbery substance are contained in the polyphenylene ether dispersed phase. A resin composition characterized in that the amount of inorganic filler contained therein is greater than the amount of inorganic filler contained in polyamide.

Preferably, the inorganic filler is dispersed in the polyphenylene ether in the form of a rubber-like substance. Also preferably 70% by weight or more of the inorganic filler, more preferably 80% by weight or more
More than 90% by weight, especially more than 90% by weight, is in polyphenylene ether and rubber-like material. The phase in which the @ material is present was confirmed by, for example, transmission electron micrographs.

In order to disperse the inorganic filler in a small amount in the polyamide matrix and in a large amount in the polyphenylene and rubber-like substance, the inorganic filler is first melt-kneaded with the rubber-like substance to form a compound, and this is mixed with the polyphenylene ether and the polyamide. All you have to do is knead it. It is also possible to first knead the compound with the polyphenylene ether and then with the polyamide. A rubbery solvent may be used in making the inorganic filler and rubbery compound, but is usually not necessary. The preferred method for kneading the compound, polyphenylene ether, and polyamide is a melt kneading method. The use of small amounts of solvent is possible, but generally not necessary.

Equipment includes extruders, Banbury mixer rollers,
Examples include kneaders and the like. Before melt-kneading, it is preferable to mix the solid components using a Henschel mixer, ribbon blender, super mixer, or the like.

During compounding of the compound with the polyamide and polyphenylene ether, a portion of the inorganic filler H is transferred to the polyamide matrix phase, but by adjusting the mixing conditions and, if necessary, the affinity of the inorganic filler and the rubber-like substance. The amount of movement can be reduced. In order to increase the affinity between the inorganic filler and the rubber-like substance, it is preferable to surface-treat the inorganic filler, using higher fatty acids such as stearic acid, oleic acid and palmitic acid, and their esters and salts as a treatment agent. Derivatives, silane coupling agents such as vinyltrimethoxysilane, γ-chloropropylethoxysilane and γ-aminopropyltriethoxysilane, titanate coupling agents such as isopropyltriisothiaroyl titanate and the like.

The inorganic filler used in the present invention may be any of the conventional inorganic fillers that are usually mixed into resin molded products, and its shape may be granular, such as spherical or cubic, plate-like, acicular, fibrous, etc. It is optional, but preferably granular. Its size needs to be smaller than the predetermined size of the polyphenylene ether dispersed phase (average 0.1 to 10μ), otherwise the size of the polyphenylene ether dispersed phase containing the inorganic filler is larger than the predetermined size. Otherwise, the inorganic filler is not included in the polyphenylene ether dispersed phase and is largely dispersed in the polyamide matrix phase, resulting in a decrease in impact resistance. The particle size of the inorganic filler mentioned here is
This is the average particle size of primary particles observed using an electron microscope or the like.

If the shape is significantly different from a spherical shape, the average particle size is considered to be half the sum of the major axis and the minor axis. Inorganic fillers include iron oxide, zinc oxide, titanium oxide, alumina, silica, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, magnesium carbonate, calcium carbonate, magnesium carbonate, calcium carbonate, barium sulfate, calcium sulfate, fa Examples include acid soda, calcium sulfite, calcium silicate, clay, wollastonite, glass peas, glass powder, glass flakes, silica sand, whitebait, diatomaceous earth, ceramic powder, and metal powder. these are,
There is no problem in using more than one.

The rubbery material used in the composition of the present invention must be rubbery at room temperature and be substantially included in the polyphenylene ether phase that forms the dispersed phase in the composition, and is more It is also necessary to have a strong affinity for polyphenylene ether. Specific examples of the rubbery substance used in the present invention include diene homopolymers such as polybutadiene and polyisoprene, butadiene-styrene random copolymers, alkenyl aromatic-conjugated diene copolymers, and partially hydrogenated products thereof. Among these, particularly preferred are partially hydrogenated alkenyl aromatic-conjugated diene block copolymers.

Such hydrogenated block copolymers include:
1 KRATON from Shell Chemical Company
- Commercially available under the trademark GJ.

The polyphenylene ether used in the present invention is known,
For example - up to (where R1, F?, 2.R3, and R4 are hydrogen, halogen, alkyl groups, alkoxy groups, haloalkyl groups having at least 2 carbon atoms between the halogen atom and the phenyl ring, and halo It refers to a monovalent substituent selected from alkoxy groups that do not contain a tertiary α-carbon, where n is an integer representing the degree of polymerization), and is a general term for polymers represented by the above - maximum The polymer may be a single type of polymer or a copolymer of two or more types in combination. In a preferred embodiment, R
and R2 is an alkyl group having 1 to 4 carbon atoms, R,
R4 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-dinityl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1
,4-phenylene)ether, poly(2-methyl-6-
Broby-1,4-phenylene)ether, poly(2,
Examples thereof include 6-diprobyl-1,4-phenylene) ether and poly(2-ethyl-6-brobyl-1,4-phenylene) ether. Further, as polyphenylene ether copolymers, alkyl trisubstituted phenols such as 2,3,6-
Copolymers containing a portion of trimethylphenol can be mentioned.

Alternatively, a copolymer in which a styrene compound is grafted onto these polyphenylene ethers may be used. As the styrene compound grafted polyphenylene ether, as a styrene compound to the above polyphenylene ether,
For example, it is a copolymer obtained by graft polymerizing styrene, α-methylstyrene, vinyltoluene, chlorostyrene, and the like.

Examples of the polyamide used in the present invention include, but are not limited to, nylon-4, nylon-6, nylon-6,6, nylon-12, and nylon-6,10. In the present invention, it is preferable to use a polyamide in which the amount of terminal amino groups is larger than the amount of terminal carboxyl groups. Such polyamides are
It can be obtained by adding an extra compound having a group that reacts with a carboxyl group, such as a diamine, during the polymerization of polyamide. Alternatively, it can also be obtained by polymerizing polyamide and then reacting it with a compound having a group that reacts with a carboxyl group.

In the present invention, the ratio of terminal amino group to terminal carboxyl group is preferably 1.01 or more, more preferably 1.1 or more. In particular, the end group ratio can be greater than or equal to 1.3.

It is preferable that the resin composition of the present invention contains the above composition components in the following proportions.

25 to 70 parts by weight of polyamide, especially 30 to 60 parts by weight, 25 to 60 parts by weight of polyphenylene ether, especially 30 to 50 parts by weight, 4 to 25 parts by weight, especially 5 to 15 parts by weight of rubbery substances, 1 to 10 parts by weight of inorganic filler. 20 parts by weight, especially 1 to 10 parts by weight.

If the polyamide is less than 25 parts by weight or if the polyphenylene ether is more than 60 parts by weight, the polyamide cannot form a continuous phase and the polyphenylene ether cannot form a dispersed phase.

If the amount of polyamide exceeds 70 parts by weight, heat resistance decreases, dimensional changes due to increased water absorption, and molding shrinkage increase, making it impractical. In order to improve the impact resistance, the rubber-like material should have at least 4 full-view areas, and if it exceeds 20 full-view areas, the mechanical strength will decrease.

In the composition of the present invention, various compatibilizers can be further added. For example, citric acid described in Japanese Patent Publication No. Sho 61-502195, maleic anhydride described in Japanese Patent Publication No. Sho 8O-11CJee, etc., or any other compatibilizer can be used.

The resin composition of the present invention may contain other resins such as polystyrene and additives such as pigments, dyes, heat resistant agents, oxidative deterioration inhibitors, weathering agents, lubricants, Mold release agent, crystal nucleating agent, plasticizer,
Flame retardants, fluidity improvers, antistatic agents, etc. can be added.

As an example polyamide, a molecule ff113. ooO, polyamide Do 6 was used.

As polyphenylene ether, poly(2,6
-cymethyl-1,4-]2elm) ether was used.

5EBS (partially hydrogenated styrene-butadiene-styrene copolymer) was used as the rubbery substance.

As an inorganic filler, baked clay (average particle size 0.8 μm)
Alternatively, titanium oxide (average particle size 0625 μm) was used.

In addition, citric acid was used as a compatibilizer.

Example 1 10 parts by weight of 5EB8 and 10 parts by weight of calcined seaweed were extruded at 280°C using a twin-screw extruder to create a pellet.

20 parts by weight of the obtained pellet, 30 parts by weight of polyphenylene ether, and 1 part by weight of citric acid were fed from the upstream part of the twin-screw extruder, and 50 parts by weight of polyamide was fed from the downstream part to create a pellet. Each test piece was molded from the obtained pellet and its mechanical properties were measured. The results are shown in Table 1.

Example 2 All 4 layers of dioxide chiku were used instead of the baking tray, and 5
An extruded pellet was prepared in the same manner as in Example 1 together with EB3 10 weights. 14 parts by weight of the obtained pellets, 40 parts by weight of polyphenylene ether, and 1 part by weight of citric acid were fed into the upstream part of a twin-screw press ratio machine, and 50 parts by weight of polyamide was fed into the downstream part.
A pellet was prepared by supplying parts by weight. Table 1 shows the results of similar measurements. A transmission electron micrograph of a molded test piece of the composition of this example is shown in FIG. The particles (dispersed phase) in the figure are polyphenylene ether, with an average diameter of 0.
The particle size is 5μ, and what shines black in the particles is titanium dioxide. The matrix phase is polyamide. 5EBS
It is not visible in this photo because it is not dyed.

Comparative Examples 1 and 2 A pellet was prepared using the same formulation as in Examples 1 and 2, respectively, but without pre-kneading 5EBS and the inorganic filler, all the components were melt-kneaded at once.

Table 1 shows the results of similar measurements.

(Effects of the Invention) According to the present invention, an [EL filler] can be blended into a resin composition containing polyamide, polyphenylene ether, and a rubbery substance without deteriorating the mechanical properties, particularly the impact resistance, of the molded product. Ta.

[Brief explanation of drawings]

The figure is an electron micrograph showing resin particle grooves and structures in the molded test piece of Example 2. 4 cm corresponds to 1 micron. Nippon GI~Plastics Co., Ltd.

Claims (1)

[Claims] 1. In a resin composition containing polyamide, polyphenylene ether, a rubber-like substance, and an inorganic filler, the polyamide forms a continuous phase, and the polyphenylene ether is dispersed in the polyamide with an average particle size of 0.1 to 10μ, and the rubber A resin characterized in that a rubber-like substance is mainly contained in the polyphenylene ether dispersed phase, and the amount of inorganic filler contained in the polyphenylene ether and the rubber-like substance is greater than the amount of inorganic filler contained in the polyamide. Composition.