Process for dyeing polyurethane foam

Polymethane foams are dyed by impregnation with an aqueous solution or dispersion of a dyestuff, the volume of the liquid being between 75 and 100% of the volume of the airspace in the foam. The foam is uniformly dyed. The impregnation may be assisted by squeezing and/or evacuation. Dyestuffs referred to and used in the examples are Duranol Red GN, Carbolan Blue B, Coornassie Fast Green GN, and Dispersol Fast Yellow. The polymethane foams used in the examples are derived from tolylene diisocyanate, water and (1) and (2), polydiethylene adipate; (3) polytetramethyleneglycol; (4) polyethylene glycol. The dyestuff liquors may contain wetting agents. After impregnation the dyed polymethanes may be heated at from 80-100 DEG C. for 15-60 minutes, washed with water and dried.