Abstract: A phenolic resin composition comprises an ester-curable phenol-aldehyde resin in alkaline aqueous solution wherein the phenol-aldehyde resin is a methylolated phenolic novolak resin. Preferably, during manufacture of the methylolated phenolic novolak resin, unreacted phenol is removed. The composition may be employed, for reaction with an organic ester hardener, as a binder in the production of foundry moulds and cores having high strength. The further incorporation of an aryloxy alcohol in the novolak resin binder additionally improves the final strength of products obtained by a gas curing technique using ester vapor, such as that of methyl formate.

Abstract: The invention relates to foundary moulding compositions useful for producing moulds for the manufacture of metal castings wherein the moulds are capable of giving castings with good surface finish without the need for conventional separate blacking applications. A foundary moulding composition of the invention comprises refractory material such as sand, alkali phenol-formaldehyde resole resin solution, carbonifiable material such as styrenated phenol, and an effective amount of an organic ester for hardening the composition. In another embodiment, the invention is a binder composition comprising alkali phenol-formaldehyde resole resin solution and carbonifiable material capable of being hardened by reaction with organic ester. In another embodiment, the invention is a curing additive for a foundry binder comprising carbonifiable material and liquid ester such as gamma-butyrolactone, and the like.

Abstract: The invention relates to foundry moulding compositions useful for producing moulds for the manufacture of metal castings wherein the moulds are capable of giving castings with good surface finish without the need for conventional separate blacking applications. A foundry moulding composition of the invention comprises refractory material such as sand, alkali phenol-formaldehyde resole resin solution, carbonifiable material such as styrenated phenol, and an effective amount of an organic ester for hardening the composition. In another embodiment, the invention is a binder composition comprising alkali phenol-formaldehyde resole resin solution and carbonifiable material capable of being hardened by reaction with organic ester. In another embodiment, the invention is a curing additive for a foundry binder comprising carbonifiable material and liquid ester such as gamma-butyrolactone, and the like.

Abstract: A foundry moulding composition comprising(a) a granular refractory material,(b) from 0.25 to 2.5% based on the weight of the refractory material of an aqueous solution of a potassium alkali phenol-formaldehyde resin, said aqueous solution having a solids content of from 50 to 75% and said resin having a weight average molecular weight (M.sub.wr) of from 700 to 2000, a formaldehyde:phenol molar ratio of from 1.2:1 to 2.6:1 and a potassium hydroxide:phenol molar ratio of from 0.5:1 to 1.2:1;(c) from 0.05 to 3% based on the weight of said aqueous solution, of at least one silane, and(d) from 20 to 110% based on the weight of said aqueous solution of at least one ester active to catalyze curing of said resin.

Abstract: A foundry moulding composition comprising(a) a granular refractory material,(b) from 0.25 to 2.5% based on the weight of the refractory material of an aqueous solution of a potassium alkali phenol-formaldehyde resin, said aqueous solution having a solids content of from 50 to 75% and said resin having a weight average molecular weight (M.sub.wr) of from 700 to 2000, a formaldehyde:phenol molar ratio of from 1.2:1 to 2.6:1 and a potassium hydroxide:phenol molar ratio of from 0.5:1 to 1.2:1;(c) from 0.05 to 3% based on the weight of said aqueous solution, of at least one silane, and(d) from 20 to 110% based on the weight of said aqueous solution of at least one ester active to catalyze curing of said resin.