Viscous material container having annularly contacting piston

摘要

Provided herein is a viscous material container that makes it unlikely that air remains in a housing when a piston is inserted from an insertion port of the housing. A first section of a housing is formed with two groove portions communicating with a first passage to discharge air in the first passage when a piston is inserted from an insertion port. The two groove portions communicate with the insertion port, and extend along a first imaginary center line.