Abstract: An improved resin coated sand for use in foundry shell-molding applications is disclosed which has increased resistance to thermal shock at the time of pouring. The improved product uses a phenolic resin as binder with aromatic compounds selected from the following generic formulae: ##STR1## The foundry aggregates are mixed with the phenolic resin and organic compounds under conventional mixing conditions to form a sand-resin mixture that can be formed into shell-molds. Upon casting the molten metal into these molds, the abrupt thermal expansion of the coated sand is controlled to eliminate the cracking that occurs when conventional phenolic-sand mixtures are employed.

Abstract: An improved resin coated sand for use in foundry shell-molding applications is disclosed which has increased resistance to thermal shock at the time of pouring. The improved product uses a phenolic resin as binder with aromatic compounds selected from the following generic formulae: ##STR1## wherein m, n, x and y are integers. The foundry aggregates are mixed with the phenolic resin and organic compounds under conventional mixing conditions to form a sand-resin mixture that can be formed into shell-molds. Upon casting the molten metal into these molds, the abrupt thermal expansion of the coated sand is controlled to eliminate the cracking that occurs when conventional phenolic-sand mixtures are employed.

Abstract: Resin coated sand for foundry shell molding operations is provided which eliminates the cracking of the molds at the time of pouring. In conventional phenolic bonded sand molds, the abrupt thermal expansion caused by the pouring of the molten metal into the mold causes the mold to crack. The resin coated sand, in this invention, is composed of foundry sand or aggregates coated with a phenolic resin which has incorporated therein, a polyethylene glycol of high molecular weight. This improved coated sand eliminates cracking at pouring and does not impair the shake-out property of the molds.

Abstract: A foundry composition adaptable to forming cores and molds comprising a foundry aggregate, a binder therefor, a catalyst and an amine, the binder being a substituted phenol.