| 摘要 |
PURPOSE:To obtain resin coated sand for casting having high fusion temp. and good collapsibility by using reaction product obtd. by reacting ester phosphate kind and/or ester phosphite kind and bisphenol A. CONSTITUTION:In order to obtain the resin coated sand for casting used for producing the casting having comparatively low casting temp., such as aluminum casting, the reaction product obtd. by reacting (a) solid phenol resin, (b) ester phosphate kind and/or ester phosphite and bisphenol A, and if necessary, (c) hexamethylenetetramine is coated on silica sand heated at 100-200 deg.C. As the solid phenol resin, solid ammonia resol resin is favorable in the collapsibility to use. As the ester phosphate kind, triphenyl phosphate is used, and as the ester phosphite kind, triphenyl phosphite, etc., is used.
|
