Substantially anhydrous foaming agent and process for producing the same

The present relates to a substantially anhydrous blowing agent and a process for producing the same. It provides a blowing agent which is significantly inhibited from solidification and is exceedingly useful as a blowing agent satisfactory in flowability, dispersibility into resins, and the like, even after the lapse of a prolonged period of time, and a process for producing the same. The blowing agent of the present invention is substantially anhydrous blowing agent, and it is obtained by treating a blowing agent with a surface-treating agent capable of removing water from the blowing agent, followed by optionally heating during or after the treatment.