Cap for a spray can, a spray can with the cap and a method for discharging residual liquid and gas in a spray can

The present invention provides a cap for a spray can which can discharge residual liquid and gas in a spray can safely at once and sufficiently afford to discharge a great deal of residual liquid. In another embodiment, the invention includes a spray can with the cap and a method for discharging residual liquid and gas in a spray can. The spray can has a recess or a projection on the top panel which is respectively engageable with the outer circumference or the inner circumference of an engage portion surrounding a stem of a can body, an insert hole into which the stem of the can body can be inserted being formed on the recess or the projection at the central part, a narrow portion with a diameter smaller than the outer diameter of the stem of the can body being formed below the insert hole, a stop plate against which residual liquid spouted from a discharge opening of the stem can be hit being arranged at a necessary portion below said narrow portion, two openings being formed at a connection portion of the narrow portion and the stop plate, the top panel of the cap being liquid-proof except for the insert hole, and spouted residual liquid which strikes against the stop plate jetting towards an outer circumference of the cap from said openings by pushing down the stem of the can body with the narrow portion to spout the residual liquid and residual gas.