| 摘要 |
PURPOSE:To prevent gelation of sand which is coated with a crystalline unsatd. polyester resin compsn. contg. an org. peroxide as a catalyst for curing during the storage thereof and to improve the strength which hot by adding a proton donating acid as a curing accelerator to the compsn. CONSTITUTION:A resin compsn. consisting essentially of a crystalline unsatd. polyester resin and contg. an org. peroxide as a catalyst for curing is incorporated further therein with 5-50pts.wt. a proton donating acid by 100pts.wt. the org. peroxide in the stage of coating sand with said resin compsn. There are many proton donating acids whether said acids are inorg. or org. and since the acids which are classified as strong acids are more preferable in order to generate proton by dissociating in the molten resin liquid and are enumerated by a hydrochloric acid, sulfuric acid, p-toluene sulfonic acid, etc. |
