Abstract: A method of manufacturing polyurethane foams comprising the steps of mixing a polyol and an organic isocyanate without causing them to substantially react with each other thereby to obtain a nonreacted mixture, mixing the nonreacted mixture with a foaming agent, a catalyst, a foam stabilizer and other necessary additives such as a pigment, a fire retardant and a filler, and injecting the resultant mixture to a mold to cause the resultant mixture to foam and crosslink. The polyol and the organic isocyanate may be preliminarily mixed with a gas such as an inert gas or air. The nonreacted mixture containing the polyol and organic isocyanate may be subjected to aging at a temperature of -10.degree. to 25.degree. C. for 12 to 27 hours.

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: A method of manufacturing a modified polyhydroxy compound, which is characterized in that a polyhydroxy compound is heated for 30 minutes or more at a temperature ranging from 150.degree. to 250.degree. C. under stirring and in the presence of tin, tin compounds such as tin halogenide, tin hydroxide and tin oxide. The polyhydroxy compound modified by this method is effective in improving the foamability and mechanical strength of urethane foam, when it is used as a raw material in the manufacture of urethane foam.

Abstract: An apparatus for continuously manufacturing polyurethane foam slabs in a batch, which comprises a cylindrical tank for developing polyurethane foam, having an inlet at the side wall thereof for introducing therein polyurethane feed solution; a stirring tank for forming polyurethane foam feed solution, which is mounted on a carriage movably placed in proximity to the cylindrical tank; stirring blades mounted within the stirring tank; a discharge pipe extending from a lower side of the stirring tank to discharge the feed solution through the inlet into the cylindrical tank; pipes for introducing raw materials into the stirring tank; and a pipe for introducing a washing solvent for removing the raw materials. The cylindrical tank is interchangeably connected with the stirring tank through the discharge pipe.

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 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.

Abstract: The invention provides a ball for a game having a spherical soft polyurethane foam and a surface layer of foamed polyvinyl chloride formed on the surface of the spherical body. The ball is produced by first casting the surface layer in a mold to form a hollow foamed PVC body having closed cells, and then charging a foamed polyurethane composition into the hollow thus formed, to produce a sphere of polyurethane having open cells within the surface layer. Also provided is a ball for games having a spherical body of foamed polyvinyl chloride and having a spherical cavity at the center. The ball is safe, has proper flexibility, and is not subject to punctures.

Abstract: A mold equipment comprising a first lift chamber at the outlet portion of a material pouring station, a heating chamber containing a curing atmosphere and connected to the outlet of the first lift chamber, a pull-in means for drawing a metal mold from the outlet of the material pouring station into the first lift chamber, a second lift chamber at the outlet portion of the heating chamber, a mold releasing work station adjacent to the second lift chamber, a third lift chamber at the outlet portion of the mold releasing work station, a cooling chamber connected to the outlet of the third lift chamber, a pull-in means for drawing the metal mold from the outlet of the mold releasing work station into the third lift chamber, a fourth lift chamber defined between the outlet of the cooling chamber and the material pouring work station, and push-in means for forcing the metal mold into the heating chamber, mold releasing work station, cooling chamber, and material pouring station, respectively.

Abstract: A method for manufacturing a low density synthetic resin foamed body is disclosed which is characterized by the steps of filling a mixture of 100 parts by weight of an ethylene-vinyl acetate copolymer, 20-80 parts by weight of a foaming agent, and 1.0-5.0 parts by weight of a crosslinking agent in a mold, closing the mold with a lid, heating the mold to form a foamed body, cooling the foamed body as it is kept in the mold, and opening the lid of the mold.

Abstract: A mold equipment comprises a water tub having a metal mold transfer conveyor therein, a first lift chamber for placing the metal mold onto a first lift from the outlet side of said conveyor and lifting it to an upper stage of the first lift chamber, a first push-in cylinder for transferring the metal mold from the outlet of the first lift chamber into a ceiling oven including a conveyor and held in an atmosphere of curing, a second lift chamber for placing said metal mold onto a second lift from the outlet of the ceiling oven and lowering it to a lower stage outlet, a second push-in cylinder for transferring the metal mold from the outlet of the second lift chamber into a mold release work station including a conveyor, a third lift chamber for placing the metal mold onto a third lift at the outlet of the mold release work station and lowering it to the position of the mold transfer conveyor in the water tub, and a third push-in cylinder for transferring the metal mold into the water tub from the outlet of sai