JPH0218341B2 - - Google Patents

Description

[Detailed description of the invention]

[]Background of the Invention The present invention relates to a method for producing a polyphenylene ether resin composition that has improved impact resistance without reducing other physical properties. Polyphenylene ether resin has excellent electrical and mechanical properties, high heat distortion temperature, and self-extinguishing properties, and is attracting attention as an extremely useful engineering plastic material. However, it is somewhat brittle due to its low impact strength. Furthermore, since this resin has a high melting temperature and high melt viscosity, high molding temperatures and pressures are required during molding, making molding by melting difficult. Therefore, as shown in Japanese Patent Publication No. 43-17812, for example, moldability is imparted by blending with polystyrene resin. Although impact resistance strength can be improved by selecting the type of polystyrene resin to be blended, it is insufficient depending on the application. In this case, there is a correlation between the impact strength of the polyphenylene ether resin composition and the rubber content in the blended high impact polystyrene resin, and the aim is to create a polyphenylene ether resin composition with improved impact strength. If so, it is necessary to blend a high impact polystyrene resin with a higher rubber content with the polyphenylene ether resin. However, there are practical limitations and commercially available high impact polystyrene resins do not have as high a rubber content as desired for this purpose. Furthermore, even if a high-impact polystyrene resin with a high rubber content were to be commercially available, it would have the disadvantage of poor moldability due to the high rubber content. Another method for improving the impact strength of polyphenylene ether resin is
As disclosed in Japanese Patent Publication No. 47-32730, there is a method of mixing polyphenylene ether resin and rubber under heating and melting using a roll mill or a Banbury mixer. Due to poor compatibility with quality,
No improvement in performance was observed due to rubber compounding.
In addition, as another improved method of blending a rubber substance into a polyphenylene ether resin, for example, as described in JP-A-46-2345, a polyphenylene ether resin and a rubber substance are dissolved in a common good solvent. After drying, a common poor solvent is added to co-precipitate the polyphenylene ether resin and the rubbery material. Although this method slightly improves the dispersibility in the rubbery polyphenylene ether resin, it does not have a significant effect on improving the impact strength. []Summary of the Invention The present inventors have improved the dispersibility of a rubber material and a composition made of a polyphenylene ether resin or a polyphenylene ether resin and a polystyrene resin, and as a result, improved impact strength. As a result of intensive study, we have arrived at the present invention. That is, in the present invention, the molecular weight is
The present invention relates to a method for producing a polyphenylene ether resin composition, which comprises adding 1 to 15 parts by weight of liquid polybutadiene rubber containing 1,000 to 5,000 epoxy groups, and then kneading while heating and melting. The method of the present invention improves the impact strength of polyphenylene ether resin compositions and, interestingly, has almost no adverse effect on other physical properties such as moldability. []Specific description of the invention (1) Polyphenylene ether resin The polyphenylene ether resin used in the present invention has the general formula It has a cyclic structural unit represented by, in which the ether oxygen atom of one unit is connected to the benzene nucleus of the next adjacent unit, n is a positive integer of at least 50, and Q is an independent Hydrocarbon groups that do not contain hydrogen, halogen, or tertiary α-carbon atoms, halohydrocarbon groups that have at least two carbon atoms between the halogen atom and the phenyl nucleus, hydrocarbon oxy groups, and halogen atoms and phenyl Represents a monovalent substituent selected from the group consisting of halohydrocarbonoxy groups having at least two carbon atoms between them and the nucleus. Typical examples of polyphenylene ether include poly(2,6-dilauryl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, and poly(2,6-diphenyl-1,4-phenylene) ether.
6-dimethoxy-1,4-phenylene) ether, poly(2,6-diethoxy-1,4-phenylene) ether, poly(2-methoxy-6-
Ethoxy-1,4-phenylene)ether, poly(2-ethyl-6-stearyloxy-1,
4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2-methyl-6-phenyl-1,4-phenylene) ether, poly(2,6-dibenzyl-
1,4-phenylene) ether, poly(2-ethoxy-1,4-phenylene) ether, poly(2-chloro-1,4-phenylene) ether,
Poly(2,5-dibromo-1,4-phenylene) ether and the like. Methods for producing polyphenylene ethers corresponding to these general formulas are known and are described, for example, in US Pat. No. 3,306,874, US Pat. No. 3,306,875, US Pat. For the purposes of the present invention, a particularly preferred group of polyphenylene ethers are those having alkyl substituents in the two ortho positions to the ether oxygen atom, i.e. each Q in the ortho position is an alkyl group, most preferably a number of carbon atoms. is a polyphenylene ether of the above general formula having 1 to 4 alkyl groups. Typical examples include 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-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl- 1,4-phenylene) ether, among which the most preferred is poly(2,6
-dimethyl-1,4-phenylene) ether. (2) Polystyrene resin The polystyrene resin used in the present invention includes GP polystyrene, high impact polystyrene, styrene/butadiene copolymer, styrene/maleic anhydride copolymer, styrene/methyl methacrylate copolymer, etc. , these polystyrene resins are used in an amount of 0 to 100 to 10 parts by weight of polyphenylene ether resin.
~90 parts by weight. (3) Epoxy group-containing liquid polybutadiene rubber Liquid polybutadiene rubber consists of 1,2-bonds and 1,4-bonds based on the fine structure of the main chain.
-Some things consist of bonds. Liquid 1,2-polybutadiene is generally synthesized by anionic polymerization, and liquid 1,4-polybutadiene is generally synthesized by coordination anionic polymerization or radical polymerization. Liquid polybutadiene rubbers include butadiene homopolymers as well as copolymers of butadiene and styrene or butadiene and acrylonitrile. The functional groups of liquid polybutadiene rubber include hydroxyl group, carboxyl group, isocyanate group, thiol group, and epoxy group, but even if liquid polybutadiene rubber having functional groups other than epoxy groups is used, there is almost no improvement in impact strength. There isn't. This suggests that the epoxy group-containing liquid polybutadiene rubber partially reacts with the polyphenylene ether resin or the composition of the polyphenylene ether resin and polystyrene resin when melt-kneaded. The epoxy groups in the epoxy group-containing liquid polybutadiene rubber can be located at both ends of the polybutadiene molecule or within the molecule. The epoxy concentration of those present at the ends of the molecule is 250 to 5000 in terms of epoxy equivalent, and the epoxy equivalent of those present within the molecule is 100 to 500. The molecular weight of liquid polybutadiene rubber containing epoxy groups is 1000 to 5000, and the viscosity is 50 at 25℃.
Poise ~ 500 poise. The amount of the epoxy group-containing liquid polybutadiene rubber added is preferably 1 to 15 parts by weight, and 3 to 10 parts by weight, based on 100 parts by weight of the polyphenylene ether resin or the composition of polyphenylene ether resin and polystyrene resin. Most preferred. If it is less than 1 part by weight, the effect will be small, and if it is more than 15 parts by weight, other physical properties will be adversely affected. (4) Blending method As a blending method to obtain the polyphenylene ether resin composition of the present invention, various commonly used methods can be applied, and for example, a mixer such as an extruder or a plastomill can be used. . At this time, flame retardants, plasticizers, stabilizers, colorants, etc. can also be blended together. Furthermore, the composition of the present invention has excellent impact resistance per se, so it is not essential to add high impact polystyrene, butadiene rubber, styrene/acrylonitrile copolymer, etc. to the composition. Specifically, each of the above components is mixed and charged into an extruder with a screw diameter of 25 mm, and the cylinder temperature is
The desired polyphenylene ether resin composition can be obtained by extruding at 240 to 330°C and a screw rotation speed of 20 to 40 rpm. In addition, using a plastomill that maintains the temperature of the melting cell at 240 to 330℃, the screw rotation speed is 20 to 300℃.
The desired product can also be obtained by melt mixing at 40 rpm for 5 to 15 minutes. Hereinafter, the present invention will be specifically explained with reference to Examples. Note that all parts in the examples are parts by weight. Example 1, Comparative Example 1 (1) Production of polyphenylene ether: 2,6-dimethylphenol was placed in a reactor equipped with a gas blowing tube, a reflux condenser, a thermometer, and a stirrer.
100 parts, cupric bromide-N,N,N',N'-tetramethylethylenediamine 1:1 complex 1.5 parts, n
- 5 parts of dibutylamine, 350 parts of benzene, and 150 parts of methanol were added, and oxygen was blown into the mixture while stirring vigorously at 30°C. After 120 minutes, the resulting slurry polymer was separated and the polymer was soaked in benzene.
The mixture was washed with a solution of 350 parts of diphenoquinone, 150 parts of methanol, and 5 parts of hydrochloric acid until the red color of diphenoquinone disappeared. After further washing with methanol, it was dried under reduced pressure at 60°C overnight. 95 parts of colorless poly(2,6-dimethyl-1,4-phenylene) ether having an intrinsic viscosity of 0.50 (measured in chloroform at 25° C.) was obtained. (2) Mixing of polyphenylene ether and epoxy group-containing liquid polybutadiene rubber: Polyphenylene ether obtained by the above method
100 parts and 5 parts of epoxy group-terminated liquid polybutadiene rubber (R-45EPT manufactured by Idemitsu Petrochemical Co., Ltd.) were melt-kneaded in a Brabender at 250°C for 10 minutes.
Thereafter, a predetermined test piece was produced using a press, and each physical property was measured. System without adding epoxy group-terminated liquid polybutadiene rubber (Comparative Example 1)
It is also shown in Table 1.

[Table] Example 2, Comparative Example 2 50 parts of polyphenylene ether obtained in Example 1,
High impact polystyrene (Asahi Dow 475D)
50 parts and 5 parts of epoxy group-terminated liquid polybutadiene rubber (R-45EPT) in a Brabender at 250°C.
The mixture was melted and kneaded for 10 minutes. Thereafter, a predetermined test piece was produced using a press, and each physical property was measured. Table 2 shows the system in which no epoxy group-terminated liquid polybutadiene rubber was added (Comparative Example 2).

[Table] Example 3, Comparative Example 3 A test piece was prepared in the same manner as in Example 2 and Comparative Example 2, except that GP polystyrene (Styron-666 manufactured by Asahi Dow Co., Ltd.) was used instead of high impact polystyrene. The results are shown in Table-3.

[Table] Examples 4, 5, Comparative Example 4 The amount of epoxy group-terminated liquid polybutadiene was 2
Test pieces were prepared in the same manner as in Example 3, except that the amounts were 10 parts, 10 parts, and 20 parts. The results are shown in Table 4.

[Table] Comparative Examples 5 and 6 Hydroxyl-terminated liquid polybutadiene rubber (R-45D manufactured by Idemitsu Petrochemical Co., Ltd.) and isocyanate-terminated liquid polybutadiene rubber (HTP manufactured by Idemitsu Petrochemical Co., Ltd.) were used instead of epoxy group-terminated liquid polybutadiene rubber.
A test piece was prepared in the same manner as in Example 3 except that -4) was used. The results are shown in Table-5.

【table】

Claims (1)

[Claims] 1. 100 parts by weight of a polyphenylene ether resin or a composition of a polyphenylene ether resin and a polystyrene resin and 1 to 15 parts by weight of an epoxy group-containing liquid polybutadiene rubber having a molecular weight of 1000 to 5000 are kneaded while heating and melting. A method for producing a polyphenylene ether resin composition.