PURPOSE: To produce molds which have high mold strength when warm and have an excellent thermal collapsing property by using resin coated sand wherein a specific glycidyl compd., a specific hardener and a phenol formaldehyde resin are used as a binder.
CONSTITUTION: The resin coated sand which is coated with (A) a polyvalent glycidyl compd. having isocyanuric rings such as triglycidyl isocyanurate or the like, (B), a hardener which does not react with the polyvalent glycidyl compd. having isocyanuric rings at an ordinary temp. and reacts therewith in a short time when heated, (C) a phenol formaldehyde resin and, if necessary, (D) a hardener for said C as a binder. The molds formed by such coated sand have stable and high mold strength when warm, and even when the molds are used for cores of light alloy castings such as aluminum, the molds have an excellent thermal collapsing property, and eliminate the need for sand burning stages for the purpose of discharging the sand.
| JPS6352736 | RESIN BINDER FOR SHELL MOLD |
OZAWA HIROSHI
HIGASHINAKAGAHA EIJI
MATSUYAMA AKIO
