Method for manufacturing membrane electrode and gas diffusion layer assembly

1. A method for manufacturing a membrane electrode and gas diffusion layer assembly, the method comprising:

applying a catalyst ink including an ionomer to a second surface of an electrolyte membrane while conveying a first sheet in which a first surface of the electrolyte membrane is supported by a back sheet;

drying the catalyst ink by blowing air vibrated with ultrasonic waves onto a surface of the catalyst ink to produce a second sheet in which a catalyst layer is provided on the second surface of the electrolyte membrane;

forming a first roll by winding the second sheet; and

producing a third sheet by stacking a gas diffusion layer on the catalyst layer and pressing the catalyst layer and the gas diffusion layer in a stacking direction as heating the catalyst layer and the gas diffusion layer to join the catalyst layer and the gas diffusion layer while conveying the second sheet unwound from the first roll.

2. The method according to claim 1 , wherein after producing the third sheet, the back sheet is peeled off from the third sheet to form a fourth sheet, and the fourth sheet is wound into a roll shape to form a second roll.

3. The method according to claim 1 , wherein an equivalent weight, which is a dry mass of electrolyte per 1 mol of sulfo group in the electrolyte membrane, of the electrolyte membrane is such a value that a first peel strength between the back sheet and the electrolyte membrane is smaller than a second peel strength between the catalyst layer and the gas diffusion layer.