ABS-formaldehyde novolak

In a phenol-formaldehyde novolak coated foundry sand composition suitable for use in forming a foundry core the improvement comprising including with the novolak 1 to 20% based on the phenol in the novolak of an acrylonitrile -butadiene-styrene terpolymer resin to form a foundry core of lower peelback then said composition without said terpolymer, said novolak having been formed from phenol and formaldehyde in the presence of an acid catalyst said terpolymer resin having been added prior to the completion of the formation of the novolak, said novolak and terpolymer being present together in an amount of 2 to 5% of the sand, said coated sand being suitable to form a foundry core of low peelback.