JPH0794600B2 - Polyphenylene ether composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition composed of polyphenylene ether, an alkenyl aromatic polymer, a rubber component, and a specific polyethylene. More specifically, it relates to a polyphenylene ether resin composition in which the balance of fluidity, impact resistance and gloss is improved by blending a specific amount of polyethylene having a specific melt flow ratio, density and melt flow rate.

Polyphenylene ether is excellent in heat resistance, mechanical properties, and electrical properties, but has drawbacks such as low fluidity and impact resistance. In order to improve such drawbacks, a method is known in which a polyphenylene ether is blended with an alkenyl aromatic polymer having excellent fluidity and compatibility and a rubber component.

However, when it is attempted to greatly improve impact resistance by increasing the rubber content in a composition in which an aromatic alkenyl polymer and a rubber component are blended in polyphenylene ether, other important properties such as fluidity and gloss are significantly reduced. descend.

Further, it is known to add polyethylene to a composition composed of a polyphenylene ether and an aromatic alkenyl polymer for the purpose of improving processability. For example, Japanese Patent Publication Sho 48-3
No. 9015 discloses that blending a low molecular weight polyolefin improves processability and anisotropy of Izod impact strength. However, it is said that blending a high molecular weight polyethylene not only lowers the Izod impact strength but also increases the anisotropy thereof. Furthermore, JP-A-52-12894
Japanese Patent Publication No. 7 describes that a small amount of low-density polyethylene is added as a processing aid.

However, these improve workability and cannot improve impact resistance at the same time.

(Summary of the Invention) The inventors of the present invention have made extensive studies in order to improve this point. As a result, molding by adding a specific polyethylene to a composition comprising a polyphenylene ether, an alkenyl aromatic polymer, and a rubber component. The present invention has been accomplished by finding that the impact resistance can be improved at the same time as the property.

More specifically, it is composed of polyphenylene ether (A), aromatic alkenyl polymer (B), and rubber component (C) in a weight ratio of (A) / (A) + (B) ≧ 0.2 (C) / (A ) +
(B) Melt flow rate (MFR) measured at a load of 2.16 kg at 190 ° C. at a melt fluidization of 10 or less, a density of 0.92 g / cm ³ or less, relative to 100 parts by weight of a composition of ≧ 0.2. Unless otherwise specified, the measurement conditions are the same.) 0.1 to 100 g / 10 min ethylene 92 to 98 wt% and α-olefin (excluding ethylene)
2 to 8% by weight of linear low density polyethylene 0.3
The present invention provides a polyphenylene ether composition having an excellent balance of fluidity, gloss and impact resistance, which is characterized by being mixed in an amount of 10 to 10 parts by weight.

The present invention significantly improves not only Izod impact strength but also falling weight impact strength.

(Specific Description) The polyphenylene ether used in the present invention is
General formula A copolymer having two or more kinds of the structural units described above within a range that does not practically lower the basic performances of the polymer or the polyphenylene ether having the unit structure represented by Is over 50. R ₁ , R ₂ ,
R ₃ and R ₄ are any of hydrogen, halogen, a hydrocarbon group or a substituted hydrocarbon group, a hydrocarbon oxy group or a substituted hydrocarbon oxy group. Specific examples of R ₁ , R ₂ , R ₃ and R ₄ include halogen atoms such as hydrogen, chlorine, bromine and iodine, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, allyl, phenyl, benzyl and methylbenzyl. Hydrocarbon groups such as, chloromethyl,
Examples thereof include substituted hydrocarbon groups such as bromomethyl, hydrocarbon oxy groups such as methoxy, ethoxy, phenoxy and chloroethoxy, and substituted hydrocarbon oxy groups.
Specifically, poly-2,6-dimethyl-1,4-phenylene oxide, poly-2,6-diethyl-1,4-phenylene oxide, poly-2,6-dipropyl-1,4-phenylene Nylene oxide, poly-2-methyl-6-isopropyl-1,4-phenylene oxide, poly-2-methyl-6-isopropyl-1,4-phenylene oxide, poly-2,6-dimethoxy-
1,4-phenylene oxide, poly-2,6-diphenyl-1,
4-phenylene oxide, poly-2,6-diphenyl-1,4
-Phenylene oxide, poly-2,6-dichloro-1,4-phenylene oxide, poly-2,5-dimethyl-1,4-phenylene oxide and other polymers, 2,6-dimethylphenol
Examples thereof include copolymers of 2,3,6-trimethylphenol and copolymers of 2,6-dimethylphenol and 3-methyl-6-tert-butylphenol.

Further, the polyphenylene ether of the present invention includes a modified product of the above-mentioned polymer or copolymer. For example, a polymer obtained by oxidatively polymerizing a (poly) alkylphenol in the presence of polystyrene, a polyphenylene ether polymer or a copolymer of styrene in the presence of a copolymer, a polyphenylene ether polymer or a copolymer. Examples thereof include those obtained by kneading and styrene together with a peroxide in an extruder and reacting.

The alkenyl aromatic polymer used in the present invention has the general formula (R ₅ , R ₆ , R ₇ , R ₈ and R ₉ are hydrogen, halogen, a hydrocarbon group or a substituted hydrocarbon group, a hydrocarbon oxy group,
It is a substituted hydrocarbon oxy group, R ₁₀ is hydrogen, and has 1 to 1 carbon atoms.
4 is a lower alkyl group. ) Is a polymer or copolymer containing 50% by weight or more of the alkenyl aromatic compound. Specific examples of R ₅ , R ₆ , R ₇ , R ₈ and R ₉ include hydrogen; halogen atoms such as chlorine and bromine; hydrocarbon groups such as methyl, ethyl, propyl, vinyl, allyl, benzyl and methylbenzyl; Substituted hydrocarbon groups such as chloromethyl and bromomethyl; hydrocarbon oxy groups such as methoxy, ethoxy, phenoxy and monochloromethoxy, substituted hydrocarbon oxy groups and the like are included. Specific examples of R ₁₀ include hydrogen; lower alkyl groups such as methyl and ethyl. Specific examples of the alkenyl aromatic polymer include polystyrene, polychlorostyrene, poly α-methylstyrene, styrene-acrylonitrile copolymer, styrene-α-methylstyrene copolymer, and styrene-4-.
Examples thereof include a methylstyrene copolymer, a styrene-maleic anhydride copolymer, a styrene-methylmethacrylate copolymer, a polybutadiene-modified impact resistant polystyrene, and a styrene-acrylonitrile-butadiene terpolymer.

The rubber used in the present invention refers to natural rubber, synthetic rubber derived from conjugated dienes, and other substances exhibiting rubber-like behavior, such as natural rubber, polybutadiene rubber, butadiene-styrene copolymer rubber. , Butadiene-acrylonitrile copolymer type rubber, butadiene-styrene-methyl methacrylate copolymer type rubber, polyisoprene rubber, ethylene-propylene copolymer type rubber,
Specific examples thereof include styrene-butadiene block copolymers and hydrogenated products thereof. These rubbers form a two-phase system in a matrix made of polyphenylene ether and an alkenyl aromatic polymer and are dispersed in the form of particles. The compounding amount of the rubber in the present invention is 100% of the total amount of the polyphenylene ether and the aromatic alkenyl polymer.
It should be 20 parts by weight or less with respect to parts by weight. A composition having a rubber content of more than 20 parts by weight is not preferable because the fluidity and gloss are significantly reduced.

Any method may be used for compounding the rubber. Method of melt kneading polyphenylene ether, aromatic alkenyl polymer, rubber, polyethylene at the same time with an extruder, heating roll, Banbury mixer, kneader, etc., melt rubber with polyphenylene ether in advance and then melt with other components There are a method of kneading, a method of adding rubber to the aromatic alkenyl polymer in advance, and a method of melt-kneading with other components, and any method can be applied. The method of adding the rubber to the aromatic alkenyl polymer in advance is a method of melt-kneading the aromatic alkenyl polymer and the rubber, or a method such as a mass polymerization method, a mass-suspension polymerization method or an emulsion polymerization method. Rubber can also be added in islands.

The polyethylene used in the present invention has a melt flow ratio of 10 or less, a density of 0.92 g / cm ³ or less, and a melt flow rate of
It is in the range of 0.1-100g / 10min.

The melt flow ratio in the present invention means a value obtained by dividing the melt flow rate measured at 190 ° C. under a load of 10 kg by the melt flow rate measured at 190 ° C. under a load of 2.16 kg.

The polyethylene used in the present invention is a so-called linear one produced by copolymerizing ethylene and a small amount of α-olefin by a known ionic polymerization method using titanium chloride or organoaluminum as a catalyst. Low density polyethylene is preferred. Specific examples of α-olefin include butene-1,4-methylpentene-1, hexene,
Examples include octene. Α-copolymerized with ethylene
The amount of olefin is usually 2 to 8% by weight, though it depends on the α-olefin species and the density.

Polyethylene produced by this method is generally characterized by less long-chain branching and narrower molecular weight distribution than polyethylene produced by radical polymerization.

The melt flow ratio of polyethylene must be 10 or less.
A preferable melt flow ratio is 8 or less. When the melt flow ratio exceeds 10, not only the effect of improving the impact resistance is poor, but it also decreases depending on the case.

The density is 0.92 g / cm ³ or less. If the density exceeds 0.92 g / cm ³ , the effect of improving impact strength is poor, which is not preferable. MF
R is in the range of 0.1 to 100 g / 10 min, preferably 0.5 to 20 g
/ 10 min. When the MFR is less than 0.1 g / 10 min, the fluidity is lowered, which is not preferable, while when the MFR is more than 100 g / 10 min, the effect of improving the impact strength is poor, which is not preferable.

In the present invention, the reason why polyethylene specifically improves impact strength is not clear, but because it is dispersed in a matrix composed of polyphenylene ether and an aromatic alkenyl polymer with a particle size effective for improving impact strength. it is conceivable that.

The present invention comprises four components of polyphenylene ether (A), aromatic alkenyl polymer (B), rubber component (C) and polyethylene (D). A suitable ratio of each component is in the range represented by formulas -2, 3, 4 by weight.

(A) / (A) + (B) ≧ 0.2 (2) (C) / (A) + (B) ≦ 0.2 (3) (D) / (A) + (B) = 0.003 to 0.1 (4) If the compounding amount of polyphenylene ether is less than 0.2, the heat resistance will decrease, which is not preferable. Further, if the compounding amount of the rubber component exceeds 0.2, the homogeneity and the gloss are significantly lowered, which is not preferable. The amount of polyethylene blended is in the range of 0.003 to 0.1, preferably 0.01 to 0.05. If the content of polyethylene is less than 0.003, the effect of improving impact strength is poor, while if it exceeds 0.1, phase separation occurs, and as a result, a layer separation phenomenon occurs in the molded product, which is not preferable.

As a method for producing the resin composition of the present invention, a known melt-kneading method can be used. For example, it can be manufactured by melt-kneading with an extruder, a heating roll, a Banbury mixer, a kneader blender or the like.

Further, it goes without saying that glass fibers, inorganic minerals such as calcium carbonate, talc, mica, etc., heat stabilizers, weathering agents, flame retardants, coloring agents and the like can be added as reinforcing agents.

Hereinafter, the present invention will be described with reference to examples in order to further clarify the present invention, but the scope of the present invention is not limited by the examples.

Examples-1 and 2, Comparative Examples 1 to 7 The concentration in chloroform was 0.5 g / dl, and the reduced viscosity at a temperature of 30 ° C was
Poly (2,6-dimethylphenol) 0.47, polystyrene HF77 manufactured by Mitsubishi Monsanto, SBR1502 manufactured by Nippon Synthetic Rubber and various polyethylenes were granulated at a ratio shown in Table 1 at 270 ° C. using a twin-screw extruder. Injection molding is N100B manufactured by Japan Steel Works
-It was performed at 290 ° C using a type II injection molding machine.

Melt flow ratio of polyethylene used in Examples and Comparative Examples,
The density and MFR are shown in Table-2.

The physical properties were measured according to the following methods.

(1) Fluidity: Using JIS K7210 equipment, 250 ℃, 10kg
MFR was measured under load.

(2) Gloss: JIS Z8741 60 ° angle (3) Izod impact strength: JIS K7110 23 ℃ with notch (4) Molten impact strength: 7 kg falling weight from 1.5 m height to thickness
The energy required for fracture was calculated from the load and strain diagram applied to the test piece by dropping it on a 2 mm sheet.

(5) Heat distortion temperature: JIS K7207 (18.5 kg / cm ² ) If a large amount of rubber is added from Table 1 to improve the impact resistance, the fluidity and gloss are significantly reduced. Further, when polyethylene other than the present invention is blended, there is no effect of improving impact resistance. On the other hand, it can be seen that the composition containing the polyethylene of the present invention has an excellent balance of fluidity, gloss and impact resistance as compared with the composition containing a large amount of rubber.

Examples-3 to 5, Comparative Examples 8 to 11 Polybutadiene in the form of polystyrene grafted elastomer gel phase in the same matrix of poly-2,6-dimethylphenol and polystyrene previously used in Example-1 was used.
2% by weight of polystyrene, triphenylphosphonate and various polyethylenes blended in the proportions shown in Table-3.
Granulation was carried out at 270 ° C. using a shaft extruder. Injection molding was performed using a Japan Steel Works N100B-II type injection molding machine with an injection pressure of 1000 kg / c.
It was carried out at m ² and a cylinder temperature of 260 ° C. The physical property evaluation results are shown in Table 3.

Examples 6-9, Comparative Examples 12-17 Polybutadiene 7 in the form of a polystyrene grafted elastomer gel phase in the same matrix of poly-2,6-dimethylphenol as previously used in Example-1 and polystyrene.
2% by weight of polystyrene, triphenylphosphonate and various polyethylene blended in the proportions shown in Table-4.
Granulation was carried out at 270 ° C. using a shaft extruder. For injection molding, use N100B-II type injection molding machine manufactured by Japan Steel Works, injection pressure 1000 kg / c
It was carried out at m ² and a cylinder temperature of 270 ° C. The physical property evaluation results are shown in Table 4.

It can be seen from Table 4 that polyethylene having melt fluidization exceeding the range of the present invention has no impact resistance improving effect, and that the amount of polyethylene of the present invention added is preferably 0.3 to 10 parts by weight.

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Claims (1)

[Claims] 1. A polyphenylene ether (A), an aromatic alkenyl polymer (B), and a rubber component (C) in a weight ratio of (A) / (A) + (B) ≧ 0.2 (C) / (A). + (B) ≧ 0.2 with respect to 100 parts by weight of the resin composition, the melt flow ratio defined by the formula-1 is 10 or less,
With a density of 0.92 g / cm ³ or less, a melt flow rate of 0.1 to 100 g / 10 min at 190 ° C and a load of 2.16 kg, 92 to 98 wt% ethylene and α
A polyphenylene ether composition comprising 0.3 to 10 parts by weight of a linear low density polyethylene composed of 2 to 8% by weight of an olefin (excluding ethylene).