Abstract: A method of producing polyurethane foam slab by allowing a urethane foam stock solution in a tank to expand in a reduced pressure. The flatness of the top of the polyurethane foam is secured by providing a lifting jig or a plate within the tank, or by rotating the tank. An apparatus for carrying out the method is also provided.

Abstract: An asphalt foam having open cells wherein asphalt mixed with an alkali metal silicate is fixed to the wall of the open cells. The asphalt foam is useful for a joint filler, a vehicle floor material, etc. A method of producing the asphalt foam, which comprises the steps of impregnating an open cell foam sheet with an aqueous mixture consisting of asphalt emulsion and an aqueous solution of an alkali metal silicate, and drying the impregnated foam sheet.

Abstract: A continuous production process for making a slab of polyurethane foam comprises preparing a foamable polyurethane composition, continuously feeding the composition to a horizontally moving trough to form a foaming mass on the trough, continuously pressing the top surface of the foaming mass with a pressure means over a zone including a zone extending from the foaming completion point to a point just prior to the completion of curing so as to make flat the top surface of the foaming mass, and horizontally moving the pressure means in synchronism with and in the same direction as the trough. Preferably, the composition is fed to the trough at such a rate as to produce a slab about 40 mm to 250 mm thick. The process can produce at a low cost polyurethane foam slabs which have no cavities and no cracks and which therefore have a uniform density or porosity.

Abstract: An antistatic polyurethane foam contains quaternary ammonium salt as an antistatic agent. The quaternary ammonium salt is added either to a raw material for polyurethane foam or to a prepared polyurethane foam by causing the foam to be impregnated with a solution containing the quaternary ammonium salt and drying it.