Abstract: A binding agent comprising 95 to 50% by weight of a furan resin, 5 to 50% by weight of lignin from the Organosolv process and organic and/or inorganic acid curing agents useful for the production of curable molding compositions, high temperature-stable molding substances and refractory products, especially casting cores and casting molds.

Abstract: A granular molding material with a binder comprising a phenol novolac and a polyisocyanate which hardens upon addition of amine catalysts wherein the molar ratio of phenol to formaldehyde in the novolac is 1:0.25 to 1:0.5 and has the formula ##STR1## wherein R, R' and R" are individually selected from the group consisting of hydrogen, alkyl of 1 to 12 carbon atoms, hydroxy, cycloalkyl of 3 to 12 carbon atoms and an anellated ring and X is an integer from 0 to 4 or >4 with the percent molar distribution based on X is as follows:______________________________________ when X = 0: 20-55% X = 1: 15-30% X = 2: 10-30% X = 3: 0-50% X .gtoreq. 4: 0-2.5% ______________________________________for the production of improved foundry cores and molds.

Abstract: A heat-hardenable binder comprising (a) a phenolic resin of a phenolic compound and formaldehyde in a molar ratio of 1:1 to 1:2 and (b) an effective amount of a hardener mixture of hexamethylenetetramine and an acidic latent hardening agent with reduced emission problems and curing rapidly.

Abstract: A binder material is disclosed formed from furfuryl alcohol suitable for the preparation of molded bodies and cores for molding for the foundry industry based on the following composition:40-60 weight percent higher molecular weight furfuryl alcohol formaldehyde condensation product28-40 weight percent lower molecular weight furfuryl alcohol formaldehyde condensation product12-25 weight percent 2,5-bis-hydroxymethylfuran0-8 weight percent furfuryl alcohol.

Abstract: Hardenable molding masses are disclosed containing an organic binder material, fillers and additives wherein the binder material after the shaping and hardening is pyrolytically decomposed. The development of harmful substances such as aromatic hydrocarbons is considerably reduced through the addition of a boron containing compound.