JPH0794599B2 - Polyphenylene ether composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyphenylene ether composition excellent in moldability, gloss and impact strength.

Polyphenylene ether has drawbacks such as excellent heat resistance, mechanical properties, and electrical properties but low fluidity and low impact resistance. In order to improve such drawbacks, a method of incorporating a rubber-modified alkenyl aromatic polymer having compatibility with polyphenylene ether has been carried out.

However, when it is attempted to greatly improve impact resistance by increasing the rubber content in a composition obtained by blending a polyphenylene ether with a rubber-modified alkenyl aromatic polymer, the fluidity and gloss are significantly reduced.

The present invention improves this point and provides a material excellent as an engineering plastic.

(Prior Art) Various methods have heretofore been attempted to improve the balance of fluidity, gloss and impact resistance of a composition comprising polyphenylene oxide and a rubber-modified aromatic polymer. For example, JP-A-58-84852 discloses a method of blending a mineral oil with a polyphenylene ether and a rubber-modified alkenyl aromatic polymer.

According to the studies made by the present inventors, although the balance of fluidity, gloss, and Izod impact strength is improved by this method, it is considered that the falling weight impact strength is still insufficient.

(Summary of the Invention) As a result of intensive studies aimed at further improving this point, the present inventors have found that a combination of a polyphenylene ether, a rubber-modified alkenyl aromatic polymer, a specific polyethylene and a specific mineral oil is used for molding. The present invention has been accomplished by finding that the impact impact strength and the falling weight impact strength can be improved at the same time as the property.

That is, the present invention provides 100 parts by weight of a composition comprising 20 to 80% by weight of polyphenylene ether (A) and 80 to 20% by weight of a rubber-modified alkenyl aromatic polymer (B) containing 5 to 15% by weight of polybutadiene. On the other hand, the melt flow ratio shown in Equation-1 is 10
Ethylene 92 having a melt flow rate (MFR; measured conditions are the same unless otherwise specified) measured at a density of 0.920 g / cm ³ , a temperature of 190 ° C. and a load of 2.16 kg of 0.1 to 100 g / 10 min.
~ 98% by weight and α-olefin (excluding ethylene) 2-8
0.3 to 12 parts by weight of linear low density polyethylene consisting of 10% by weight, and 0.2 to 0.2% of mineral oil having a viscosity-density constant of 0.819 or less.
The present invention provides a polyphenylene ether composition having an excellent balance of fluidity, gloss, and impact resistance, which is characterized by containing 8 parts by weight.

(Detailed Description of the Invention) 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. R ₁ , R ₂ , R ₃
Specific examples of R ₄ include hydrogen, halogen atoms such as chlorine, bromine and iodine, hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, allyl, phenyl, benzyl and methylbenzyl,
Examples thereof include substituted hydrocarbon groups such as chloromethyl and bromomethyl, hydrocarbon oxy groups such as methoxy, ethoxy, phenoxy and chloroethoxy, and substituted hydrocarbon oxy groups. Specifically, poly-2,6-dimethyl-1,4
-Phenylene ether, Poly-2,6-diethyl-1,4-phenylene ether, Poly-2,6-dipropyl-1,4-phenylene ether, Poly-2-methyl-6-isopropyl-1,4 -Phenylene ether, poly-2-methyl-6-
Isopropyl-1,4-phenylene ether, poly-2,6-
Dimethoxy-1,4-phenylene ether, poly-2,6-diphenyl-1,4-phenylene ether, poly-2,6-diphenyl-1,4-phenylene ether, poly-2,6-dichloro- 1,4-phenylene ether, poly-2,5-dimethyl-
Polymers such as 1,4-phenylene ether, copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol,
Examples thereof include copolymers such as a copolymer 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, the formula in the presence of polystyrene In the extruder, oxidatively polymerized monomer represented by, polymerized styrene in the presence of polyphenylene ether polymer or copolymer, polyphenylene ether polymer or copolymer and styrene with peroxide Examples include kneaded and reacted products.

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 halogen atoms such as hydrogen, 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, polystyrene, polychlorostyrene, poly α-methylstyrene, styrene-acrylonitrile copolymer, styrene-α-methylstyrene copolymer, styrene-4-methylstyrene copolymer, Examples thereof include styrene-maleic anhydride copolymer, styrene-methyl methacrylate copolymer, polybutadiene-modified impact-resistant polystyrene, and styrene-acrylonitrile-butadiene terpolymer. Of these, polystyrene is particularly preferable.

The rubber-modified alkenyl aromatic polymer (B) component of the present invention is obtained by modifying the alkenyl aromatic polymer with rubber, that is, the rubber dispersed in the alkenyl aromatic polymer matrix. The rubber used here is polybutadiene. A butadiene-styrene copolymer obtained by copolymerizing a small amount of styrene is also included.

The amount of rubber is 5 to 15% by weight. It is more preferably 7 to 12% by weight. If the amount of this rubber is less than 5% by weight, sufficient impact resistance cannot be obtained, while if it exceeds 15% by weight, fluidity,
It is not preferable because it reduces the gloss.

Various methods are known for dispersing rubber in an alkenyl aromatic polymer, and any method may be used. For example, there are a mechanical mixing method, a solution blending method, and the like. Particularly, a method of dissolving and polymerizing a rubber in an alkenyl aromatic monomer is industrially performed.

When a rubber-modified alkenyl resin having a low rubber content is used, polybutadiene or a polybutadiene-styrene copolymer may be added.

The polyethylene (C) used in the present invention has a melt flow ratio of 10 or less, a density of 0.920 g / cm ³ or less, and a melt flow rate (MFR) of 0.1 to 100 g / 10 min.

The melt flow ratio in the present invention is 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 216 kg.

The polyethylene used in the present invention is a so-called line produced by copolymerizing ethylene with a small amount of one or more α-olefins 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 and octene.
The amount of α-olefin copolymerized with ethylene depends on the type of α-olefin, but is usually 2 to 8% by weight. Polyethylene produced by this method generally has less long chain branching than polyethylene produced by radical polymerization. It has features such as narrow molecular weight distribution.

The melt flow ratio of polyethylene must be 10 or less.
A preferable melt flow ratio is 8 or less. If the melt flow ratio exceeds 10, not only the effect of improving impact resistance is poor, but it is sometimes lowered.

The density is 0.920 g / cm ³ or less. If the density exceeds 0.920 g / cm ³ , the impact strength improving effect is poor, which is not preferable.

MFR is in the range of 0.1 to 100 g / 10 min, preferably 0.5
~ 20g / 10min. 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.

The reason why the polyethylene used in the present invention specifically improves the impact strength in combination with mineral oil is not clear, but a matrix which becomes a polyphenylene oxide and a rubber-modified alkenyl aromatic polymer with a particle size effective for improving the impact strength. It is thought that it is dispersed in the inside.

The mineral oil (D) used in the present invention is defined as an organic oily substance, and its useful one has a viscosity-density constant of 0.819 or less.

If the viscosity-density constant of the mineral oil exceeds 0.819, the impact resistance cannot be improved, which is not preferable.

Here, the viscosity-density constant is based on the calculation method of Sun Oil Company and is a value obtained by the following formula.

G: Density at 60 ° F V ₁ : Saybolt's Universal Viscosity at 210 ° F Viscosity-Density constants allow mineral oils to be grouped according to their constituents. The groups are said to be:

Viscosity-Density constant Mineral oil type ~ 0.819 Paraffin type 0.820 ~ 0.849 Approximate naphthene type 0.850 ~ 0.899 Naphthene type 0.900 ~ 0.949 Approximate aromatic type 0.950 ~ 0.999 Aromatic type 1.000 ~ 1.049 High aromatic type> 1.050 Polar aromatic type The invention is suitable for mineral oils having a viscosity-density constant of 0.819 or less,
Paraffin mineral oil is applicable.

Generally, a paraffinic mineral oil having a viscosity-density constant of 0.819 or less usually contains about 70% by weight of a paraffinic saturated hydrocarbon. Specific examples of the paraffin mineral oils include Diana Process Oil pw-90 and pw-380 manufactured by Idemitsu Kosan.

The method of adding the steel oil may be any method. For example, a method of adding when producing a rubber-modified alkenyl aromatic polymer, a method of adding when blending a polyphenylene oxide and a rubber-modified alkenyl aromatic polymer, polyethylene,
Alternatively, a method of forming a so-called master batch blend in which a large amount of mineral oil is mixed with a polyphenylene oxide or a rubber-modified alkenyl aromatic polymer and adding the polyphenylene oxide with the rubber-modified alkenyl aromatic polymer or polyethylene when blending And so on.

The present invention provides polyphenylene oxide as the component (A),
The component (B) is a rubber-modified alkenyl aromatic polymer containing a polybutadiene component as a rubber component in an amount of 5 to 15% by weight, and the component (C) is polyethylene (D). A suitable proportion of each component is a composition comprising 20 to 80% by weight of polyphenylene oxide and 80 to 20% by weight of a rubber-modified alkenyl aromatic polymer.
0.3 to 12 parts by weight per 100 parts by weight, preferably 0.3 to 10
Parts by weight, more preferably 1.0 to 5.0 parts by weight of polyethylene and 0.2 to 8 parts by weight, preferably 0.2 to 5 parts by weight, more preferably 1 to 3 parts by weight of mineral oil.

If the proportion of polyphenylene oxide is less than 20 parts by weight, the heat resistance will be lowered, and if it exceeds 80 parts by weight, the fluidity will be lowered, which is not preferable. If the amount of the rubber-modified alkenyl aromatic polymer is more than 80 parts by weight, the heat resistance is lowered, and if it is less than 20 parts by weight, the fluidity is lowered, which is not preferable. If the proportion of polyethylene is less than 0.3 part, the effect of improving impact resistance is poor, while if it exceeds 12 parts by weight, phase separation occurs, and as a result, a layer separation phenomenon occurs in the molded product, which is not preferable. If the proportion of mineral oil is less than 0.2 parts by weight, the effect of improving impact resistance is poor, while if it exceeds 8 parts by weight, the fluidity is improved but the heat resistance is lowered and a balanced quality cannot be obtained.

The method for producing the resin composition of the present invention is not particularly limited, but a melt kneading method using a Banbury mixer, an extruder, a kneader, etc. is suitable.

In addition, in the present invention, a heat stabilizer that is usually used,
Additives such as flame retardants, pigments, fillers, plasticizers, lubricants, and ultraviolet absorbers may be added as long as the physical properties do not change significantly. Further, a fiber reinforcing agent such as glass fiber, asbestos fiber, carbon fiber or the like can be added.

Next, the present invention will be described by way of examples, but the scope of the present invention is not limited by the examples.

Example-1, Comparative Examples-1 to 6 Concentration in chloroform 0.5g / dl, reduced viscosity at a temperature of 30 ℃
A rubber-modified polystyrene, triphenyl phosphate and various mineral oils and polyethylene were prepared by mixing 7% by weight of polybutadiene in the form of a polystyrene grafted elastic gel phase in a matrix of poly (2,6-dimethylphenol) of 0.50 and polystyrene in advance. Granulation was carried out at 270 ° C. using a twin-screw extruder at the ratio shown in −1. The injection molding was performed using an N100B-II type injection molding machine manufactured by Japan Steel Works at an injection pressure of 1000 kg / cm ² and a cylinder temperature of 260 ° C. The physical property evaluation results are shown in Table 1.

From Table-1, when only mineral oil is blended, the Izod impact strength is improved but the falling weight impact strength is not improved.
When the melt flow ratio of polyethylene combined with mineral oil exceeds the range of the present invention, the effect of improving impact strength is poor, and when the viscosity-density constant of mineral oil combined with polyethylene exceeds the range of the present invention, impact strength is improved. It can be seen that the effect is poor.

Examples-2-5, Comparative Examples-7-9 The same polyphenylene ether as used in Example-1,
The rubber-modified polystyrene, the rubber-modified polystyrene having a rubber content exceeding the range of the present invention, polyethylene, and mineral oil were granulated at 270 ° C. using a twin-screw extruder in a ratio shown in Table 2.
The injection molding was carried out using the same apparatus as in Example-1 with an injection pressure of 1000 kg.
/ cm ² , and the cylinder temperature was 290 ° C. The physical property evaluation results are shown in Table 2.

Examples-6 to 9, Comparative Example-10 The same polyphenylene ether as used in Example-1,
Rubber-modified polystyrene, triphenyl phosphonate,
Mineral oil and polyethylene were granulated at a ratio shown in Table 3 at 270 ° C using a twin-screw extruder. Injection molding is N100B manufactured by Japan Steel Works
-The injection was performed using a type II injection molding machine at an injection pressure of 1000 kg / cm ² and a cylinder temperature of 260 ° C. The physical property evaluation results are shown in Table 3.

Claims (1)

[Claims] 1. A rubber-modified alkenyl aromatic polymer (B) containing 5 to 15% by weight of a polyphenylene ether (A) and a polybutadiene component and having a weight ratio of (A) / (A) + (B) ≧ 0.2. With respect to 100 parts by weight of a certain resin composition, the melt flow ratio defined by the formula-1 is 10 or less, the density is 0.920 g / cm ³ or less, 190 ° C., ethylene having a melt flow rate of 0.1 to 100 g / 10 min at 2.16 kg load. 92-98% by weight and α
-0.3 to 12 parts by weight of linear low density polyethylene composed of 2 to 8% by weight of olefin (excluding ethylene) and 0.2 to 8 parts by weight of mineral oil having a viscosity-density constant of 0.819 or less. A polyphenylene ether composition.