| 摘要 |
PURPOSE:To improve a rate of carbonization and to obtain a binder having a considerably improved collapsing property by modifying a phenolic resin with a polysaccharide in a phenolic resin binder formed by dissolving phosphate, etc. CONSTITUTION:A binder is formed by dissolving >=1 kind among phosphate, phosphite, phosphonate and phosphine at 10-50pts. in a resin formed by using 10-100pts. a polysaccharide and 3-30pts. formaldehyde basing on 100pts. a phenol by weight and co-condensating these materials by an acid catalyst. Such binder is used together with coated sand in a sand mold particularly for a casting of a relatively low casting temp., such as Al casting, alloy casting or the like, whereby the casting mold is collapsed only by the mechanical impact without requiring any heat treatment after casting. |
