Abstract: The present invention relates to a double-structure aerosol container for a two-agent type hair cosmetic, having an outer vessel and an inner bag to be housed in the outer vessel. An inner bag includes an inner layer and an outer layer both of which are formed of a polyolefin resin and an intermediate layer formed of a cyclic olefin copolymer or an amorphous polyester resin, thereby preventing an inner surface of the outer vessel from corrosion after storing at high temperature with the inner bag filled with a second agent containing hydrogen peroxide as a major ingredient and at least one of an organic acid or an organic acid compound.

Abstract: A jet pickling apparatus for pickling the surfaces of continuously moving sheet material (12) has tips of the nozzle headers (41-43) for discharging a pickling fluid (19) on the surfaces of the sheet and into a pickling tank (31) formed into a slit shape (41a-43a), and the nozzles (41,42) at the entrance side are installed to eject pickling fluid in the same direction as the running direction of sheet while the nozzle (43) at the exit side ejects the pickling fluid in the direction opposite to the running direction of the sheet. Therefore, there is no gas in the pickling tank (31) and the tank is filled with the pickling fluid (19), which eliminates the problems of floating of the sheet (12) and insufficient contact of the pickling fluid (19) with the sheet surfaces, allowing thorough pickling and improving the pickling effect.