| 摘要 |
PURPOSE:To obtain the subject resin particles, having a specific component composition, excellent in casting surfaces without any cavity, good in appearance and dimensional accuracy with a small amount of cementation and suitable for molding an original mold capable of providing high-strength castings in the case of stainless steel. CONSTITUTION:Expandable methyl methacrylate-based resin particles consisting of 50-80wt.% methyl methacrylate, 12-45wt.% styrene and 5-8wt.% alpha- methylstyrene. The respective components are subjected to suspension polymerization in the presence of a polymerization initiator, such as benzoyl peroxide, in an aqueous medium at 95-130 deg.C temperature. |
