PROBLEM TO BE SOLVED: To provide a gasket laminated with an inert resin film which has a reduced slide resistance value and high liquid encapsulation performance.SOLUTION: A gasket 10 for use in a medical syringe 30 is provided that comprises: a body 11 comprised of an elastic body and an inert resin film 12 laminated on the surface of the body 11. The gasket 10 has a short columnar shape and has, on the outer circumferential surface 20 of the columnar shape, a plurality of annular ribs 13, 14 and 15 with sliding portions 16 to slide with the inner circumferential surface of the syringe. The plurality of annular ribs are aligned in an axial direction from the distal end of the gasket 10 toward its rear end, the linear length (a length in the axial direction) of the sliding portion of the annular rib 13 at the distal end occupying a ratio of 1-25%, with respect to the linear length of the outer circumferential surface 20 (a length in the axial direction of the outer circumferential surface) of the columnar shape.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT
