Process for production of polyphenylene ether resin molded article

Abstract

Provided is a process for producing a pellet that has good color and does not undergo the deterioration in physical properties from a polyphenylene ether resin raw material and a polystyrene resin raw material with high production efficiency. Specifically provided is a process for producing a polyphenylene ether resin molded article (a pellet) by kneading a polyphenylene ether resin and a polystyrene resin with each other in a molten state and carrying out the extrusion molding of the kneaded material. The process is characterized in that 1) the polyphenylene ether resin to be used is a granular material which is produced by compressing a powdery material of a polyphenylene ether resin having a toluene concentration of 0.01-0.5 mass% at a temperature equal to or lower than Tg to solidify the powdery material and, if necessary, grinding a solidified material and which has an average particle diameter of 0.1-10 mm, an apparent density of 0.35-0.7 g / cm3 and a toluene concentration of 0.01-0.5 mass%, 2) the polystyrene resin to be used is a particulate material having an average particle diameter of 1-5 mm and an apparent density of 0.5-0.7 g / cm3, and these materials are fed into an extruder, heated, molten, kneaded and extruded.

Description

technical field [0001] The present invention relates to a method for producing a polyphenylene ether-based resin molded article, and more specifically, to a method for producing a polyphenylene ether-based resin molded article that produces a polyphenylene ether-based resin molded article with a good color tone with high productivity . Background technique [0002] Polyphenylene ether-based resins are engineering plastics excellent in heat resistance, electrical properties, and chemical resistance, but on the other hand, they have disadvantages of poor fluidity and difficult molding. In addition, polyphenylene ether-based resin products taken out of the polymerization apparatus are usually in the form of powder, which is disadvantageous from the viewpoint of molding processability. Therefore, a polystyrene-based resin blended material has been developed to improve the molding processability, fluidity, and impact resistance of polyphenylene ether (see Patent Document 1), and...

AI Technical Summary

Problems solved by technology

[0004] However, when polystyrene resin is blended into polyphenylene ether resin powder and supplied to an extruder for extrusion molding, it is easy to mix air with the powdery resin, and this air-containing powder is easy to flow in the extruder. The screw conveying surface slides, so the screw conveying is unstable, and the residence time in the extruder becomes longer, which easily leads to oxidation and deterioration of the polyphenylene ether resin

[0005] In order to prevent oxidative deterioration, there is usually a method of adding an antioxidant to the raw material (see Patent Document 2), but the effect is not sufficient with this method alone. In addition, a method of supplying an inert gas such as nitrogen to the extruder is also carried out ( Referring to Patent Document 3), the effect is not sufficient when only simply supplying an inert gas

[0006] Especially when polyphenylene ether-based resins have to increase the molding temperature due to their high glass transition temperature (Tg: about 210°C), it is easy to cause discoloration due to thermal modification, even when polystyrene-based resins are mixed. In the case of the case, the discoloration problem is also larger

[0007] Furthermore, when using the powder product directly taken out from the polymerization apparatus as the polyphenylene ether-based resin, the powder product is powdery and has a low apparent density, and air is mixed into the extruder when it is supplied to the extruder. The poor bite in the feeding part (supply part) is easy to cause a feed neck (feed neck)

In addition, there is a problem that when the resin is melted in a kneading section such as a kneading disk section in the extruder, the air flows back, which hinders the transportation of the resin and reduces the extrusion amount, resulting in a sudden drop in productivity.

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