Abstract: A producing method for a resin container includes a first injection molding step of injection-molding an intermediate molded body that has a bottomed cylindrical shape and is made of resin, a second injection molding step of injection-molding a resin material into the intermediate molded body to produce a multilayer preform in which a resin layer is laminated on the intermediate molded body, and a blow molding step of blow-molding the multilayer preform in a state of having residual heat from injection molding to produce a resin container. The multilayer preform is formed such that a bottom portion is thicker than a body portion. In the blow molding step, at least one surface of the bottom portion of the multilayer preform is pressed with a mold, and a three-dimensional pattern corresponding to the mold is transferred to a thick bottom portion of the resin container.

Abstract: A temperature adjustment mold for adjusting a temperature of a preform that is injection-molded, has a bottomed shape, and is made of resin includes one or more adjusting portions that face a part of an outer peripheral surface of a body portion of the preform and locally heat a predetermined portion in a circumferential direction of the preform. The adjusting portion is disposed such that a gap is formed in the circumferential direction, and an attachment position is adjustable in the circumferential direction.

Abstract: - - - A method of producing a resin container includes injection-molding a resin intermediate molded body of bottomed cylindrical shape as a first injection-molding, injection-molding a resin material outside the intermediate molded body as a second injection-molding, to produce a multilayer preform in which a resin layer is layered on an outer peripheral side of the intermediate molded body, and a blow-molding the preform in a state of containing residual heat from injection-molding to produce a resin container having a bottom portion thicker in wall thickness than a body portion. A portion of the inner peripheral side of the intermediate molded body, the portion reaching a bottom portion of the intermediate molded body, has a tapered region in which the wall thickness increases toward the bottom portion.