Abstract: Disclosed is a 1,3-butadiene separation and recovery method which can reduce the amount of 1,3-butadiene polymer produced when 1,3-butadiene is separated and recovered from a mixed fluid containing 1,3-butadiene. The method includes an extractive distillation step of performing extractive distillation of the mixed fluid to obtain a fraction containing crude 1,3-butadiene, and a dividing wall distillation step of performing dividing wall distillation of the fraction containing crude 1,3-butadiene to obtain a fraction containing an impurity having a higher boiling point than 1,3-butadiene, a fraction containing an impurity having a lower boiling point than 1,3-butadiene, and a fraction containing high-purity 1,3-butadiene.

Abstract: Disclosed is a 1,3-butadiene separation and recovery method which can reduce the amount of 1,3-butadiene polymer produced when 1,3-butadiene is separated and recovered from a mixed fluid containing 1,3-butadiene. The method includes an extractive distillation step of performing extractive distillation of the mixed fluid to obtain a fraction containing crude 1,3-butadiene, and a dividing wall distillation step of performing dividing wall distillation of the fraction containing crude 1,3-butadiene to obtain a fraction containing an impurity having a higher boiling point than 1,3-butadiene, a fraction containing an impurity having a lower boiling point than 1,3-butadiene, and a fraction containing high-purity 1,3-butadiene.

Abstract: A handle device for a vehicle door is provided in which a tact switch that can switch between switching modes in response to a pressing-in operation of an operating button is housed and fixed within a housing recess of a handle main body so as to be electrically connected to printed wiring of a board. The printed wiring is disposed at a different site from one face, facing a cover member side, of the board, the tact switch which is fixed to the one face of the board is electrically connected to the printed wiring, a flange portion abutting against the one face of the board is provided integrally with a switch cover covering the tact switch and connected to the operating button, and the push-in stroke of the operating button is restricted to a predetermined value or below with a hold-down member engaged with the handle main body.

Abstract: A handle device for a vehicle door is provided in which a tact switch that can switch between switching modes in response to a pressing-in operation of an operating button is housed and fixed within a housing recess of a handle main body so as to be electrically connected to printed wiring of a board. The printed wiring is disposed at a different site from one face, facing a cover member side, of the board, the tact switch which is fixed to the one face of the board is electrically connected to the printed wiring, a flange portion abutting against the one face of the board is provided integrally with a switch cover covering the tact switch and connected to the operating button, and the push-in stroke of the operating button is restricted to a predetermined value or below with a hold-down member engaged with the handle main body.