PURPOSE: To provide resin coated sand which prevents the generation of crack in a shell mold after charging of molten metal, has no mal-odor and retains an original collapsing property without decreasing by coating a refractory granular material for casting with a phenolic resin compounded with petroleum pitch.
CONSTITUTION: 0.5W40pts.wt. petroleum pitch is compounded with 100pts.wt. phenolic resin in the stage when the reaction of phenols and aldehydes initiates, during the reaction or when the reaction ends in the stage of producing a phenolic resin. The compounding is accomplished by a method of, for example, grinding and mixing both. A lubricant such as ethylene-bis stearamide is added to said mixture preferably at ≤10pts.wt. in 100pts.wt. phenolic resin. The above- described phenolic resin compounded with the petroleum pitch is mixed with sand grains for casting preferably by a dry hot coating method, whereby the intended resin coated sand is obtained. For example, a novolak type phenolic resin is used for the above-described phenolic resin.
| JPS60101134 | [Title of the device] Structural panel |
SAEKI YUKIO
TOKUNAGA YUKIO
