| 摘要 |
PURPOSE:To provide a resin compsn. for binding of molding sand grains of an improved melt sticking point without degrading strength by compounding specific unstad. polyester, unsatd. monomers or prepolymers, catalysts for polymn. and selected metallic oxides. CONSTITUTION:A compsn. for binding of molding sand grains contg. unsatd. polyester which is solid at an ordinary temp., unsatd. monomers or prepolymers having <=1 unsatd. bonds in a molecule (e.g.; diallyl phthalate polymer), catalysts for polymn. such as dicumyl peroxide and oxides of metals of groups I, II, IV, VIII such as magnesium oxide and zinc oxide. According to need, lubricants, hardening accelerators, polymn. inhibitors, fillers, silane coupling agents, etc. are contained in said compsn. The compsn. is dissolved in a suitable solvent and the soln. is coated on sand grains and the solvent is allowed to evaporate, whereby resin coated sand is prepared. The melt sticking point of the coated sand is increased by the use of such compsn. |
