| 摘要 |
PROBLEM TO BE SOLVED: To markedly decrease fine particles in a resin powder and obtain an improved powder excellent in powder characteristics, handling properties and extrusion molding productivity by subjecting a polyphenylene ether resin powder to compression molding at a specific temperature and re-crushing the obtained molded product. SOLUTION: A polyphenylene ether powder containing at least 0.005 wt.% of fine particles having a particle size of 0.5μm or less is subjected to compression molding within the temperature range from 5 deg.C to 200 deg.C to give a molded product having a density of 0.7-1.055 g/cm3. The obtained molded product is crushed again by means of a crusher to give a polyphenylene powder having an improved grain size distribution containing not more than 0.5 wt.%, of all powder, of fine particles having a particle size of 1μm or less. Further, re- crushing is preferably carried out so that the ratio of particles having a particle size of 3μm to 5 mm present in the powder is at least 90 wt.% of all. This method improves a powder containing fine particles, having a small average particle size and accordingly no good handling properties into a powder containing little fine particles with an appropriately uniform grain size. |
