| 摘要 |
PURPOSE:To improve the productivity of a casting mold by using a phenolic resin, etc., as a main material for an acid curing resin and constituting a binder in such a manner as to satisfy specific condition equation and to have a prescribed weight average mol.wt. CONSTITUTION:The acid curing resin is mainly constituted of the phenolic resin or a furan resin formed by mixing or co-condensation with the phenolic resin in an acid curing cold box method in which the binder of the acid curing resin is cured by an oxidizing agent consisting of a peroxide and sulfur dioxide. The average mol.wt. thereof is controlled to a 300-5,000 range in this stage and the binder is so formed as to satisfy the conditions expressed by the equation I. Such resin is formed by the condensation reaction of the phenolic compd. and aldehyde and contributes to the remarkable improvement in the strength of the casting mold without deteriorating other performance. The productivity of the casting mold is thus improved. |
