Abstract: A golf club head having the center of mass located below the half face height. The club head includes a top surface, a sole disposed opposite to the top surface, a toe portion, a heel portion opposite to the toe portion, a front, impact face located between the toe and heel portions, a rear portion located opposite to the face and between the toe and heel portions. The toe and rear portions together form a smooth, continuous, enlarged side surface so that an upper section of the club head above the horizontal center plane, which passes the half height of the face portion, has a volume smaller than that of a lower section of the club head below the horizontal center plane.

Abstract: A crystalline resin sheet having one, smooth surface and the other, roughened surface is produced by extruding a melt of the resin through a die to form a molten sheet, the molten sheet being subsequently contacted, at only one of the both surfaces thereof, with a cooled, smooth surface maintained at a temperature lower by 20.degree.-90.degree. C. than the melting point of the resin to solidify the molten sheet and to make the contacted surface of the sheet smooth. The other surface of the sheet which has not been contacted with a cooled surface becomes roughened because of the crystallization of the resin.

Abstract: An expandable, powder coating composition is disclosed which comprises (a) a thermoplastic resin containing a copolymer of ethylene with vinyl acetate, (b) a cross-linking agent containing an organic peroxide, (c) a blowing agent, and (d) an organic plasticizer. Powder coating of a surface of a tube or box to be used in air conditioners with the coating composition can give a heat-insulating, foamed sheath or lining over the surface.

Abstract: An expandable, powder coating composition is disclosed which comprises (a) a thermoplastic resin containing a hydroxyl group-containing polymer, (b) a cross-linking agent containing a polyisocyanate compound which is capable of reacting with the hydroxyl groups of the polymer to crosslink the polymer at a temperature higher than the melting point of the thermoplastic resin and which is solid at room temperature, and (c) a blowing agent capable of decomposing and generating a gas when heated to a temperature higher than the melting point of the thermoplastic resin. Powder coating with the coating composition can give a heat-insulating, foamed sheath or lining over the surface of a metal tube or box to be used in air conditioners.