Process of preparing sand cores by using oxazoline condensates

Claim 1

A process for preparing a non-polluting sand core for production of metal castings comprising the steps of mixing said sand with an oxazoline in a proportion of about 0.5-5.0% by weight of the sand and a mixture of 3-7% or up to 10% by weight of peroxide alone or in combination with metal driers based on the weight of said oxazoline, and placing the mixture thereby obtained in a mold to harden at ambient temperatures wherein said oxazoline is (a) a mono-oxazoline corresponding to the formula ##EQU10## wherein R 1 and R 2 are methyl, ethyl, hydroxymethyl or acyloxymethyl corresponding to the formula ##EQU11##and are the same or different, R is an alkenyl group of from 1 to 18 carbon atoms, and X is H 2 , or (b) a bis- or tris-oxazoline corresponding to the formula ##EQU12##where R 3 is the group ##EQU13##wherein X 1 is any divalent or trivalent unsaturated aliphatic hydrocarbon group of from 0 to 32 carbon atoms, and when X 1 is divalent, R 4 is hydrogen and when X 1 is trivalent, R 4 is the group ##EQU14##wherein Y is an unsaturated hydrocarbon of 16 carbon atoms or (c) mixtures thereof.