Impression material cartridge gasket having air vent hole formed therein

An impression material cartridge gasket comprising:

• a gasket main body (110) moved upwards and downwards along an inner wall surface of a cylinder depending on injection and discharge of a liquid chemical;
• and
• a sealing member (120) coupled to an outer circumferential surface of the gasket main body (110) and configured to prevent leakage of the liquid chemical, wherein:
• the gasket main body (110) comprises:
• a contact protrusion (115) formed to protrude radially outwards in a height direction of a side wall (113) and configured to contact the inner wall surface of the cylinder;
• an air residual groove (114) formed to be recessed radially inwards at a lower portion of the contact protrusion (115) and configured to allow air to remain therein;
• and
• an accommodation groove (117) formed to be recessed radially inwards between an upper surface of the gasket main body (110) and the contact protrusion (115), the accommodation groove allowing the sealing member (120) to be coupled thereto, and
• the contact protrusion (115) has at least one air vent hole (119) provided circumferentially on a plate surface thereof, wherein the at least one air vent hole is formed to be recessed toward the accommodation groove (117) by a predetermined depth so as to discharge the air remaining in the air residual groove (114) to an outside of the impression material cartridge gasket.