Abstract: A method for manufacturing a phenolic resin foam is provided which comprises the steps of mixing a composition consisting of 100 parts by weight of a resol-type phenol-formaldehyde resin, 5 to 40 parts by weight of a curing agent consisting of an acid, and a foaming agent consisting of an isocyanate or a mixture thereof with water, and heating the composition for foaming, an amount of the isocyanate being 5 to 30 parts by weight if the foaming agent is the isocyanate alone, and the amount of the isocyanate being not less than its equivalent weight and an amount of water being 5 to 30 parts by weight if the foaming agent is the mixture of the isocyanate with water. If 100 parts by weight of a urethane-modified phenol-formaldehyde resin are used in place of 100 parts by weight of the resol-type phenol-formaldehyde resin, 0.1 to 1.5 parts by weight of a curing agent consisting of a tin compound are used in place of the acid curing agent.

Abstract: A process for regenerating a resin, comprises the steps of dissolving a waste resin in an organic solvent to provide a resin solution, mixing the resin solution with a liquid of normal temperature, the liquid being immiscible with the solvent, scarcely dissolving the resin, and having a specific gravity smaller than that of the solvent and larger than that of the resin, thereby separating the resin from a mixture of the resin solution and the liquid, and recovering the resin. The liquid may have a temperature higher than the boiling point of the solvent. In this case, the solvent evaporation takes place together with the resin separation. The evaporated solvent is cooled later for recovery of the solvent.