Syringe, its sealing structure and sealing method and sliding valve for syringe

Abstract

As a sealing structure for a syringe, a waterproofing film is adhered to the surface of a cap (6), a barrel (3) and a cylinder body (2) to cover fitting areas therebetween. The film is made of synthetic resin having a melting point higher than the temperature of flowing water vapor in post sterilization. As a sliding valve for a syringe, an inclined lip (24) is continuously protruded from the outer surface of a short cylindrical body (22). At the one end of the body, an annular lip (23) is formed. The inclined lip has a recess (34) for introducing a medicine liquid. The inclined lip may be formed in plural pairs of inverted , in plural stages, in plural strips in an axial direction, or in a shape to cross to form a sea slug wall. The sliding valve can be inserted with no inclination so that stagnant of air is not produced. As a syringe, at the tip of a cylinder, a bulging portion (87) having a larger inner diameter than that of the cylinder is formed integrally to the cylinder and the inner diameter of said bulging portion is larger than the outer diameter of an elastic sliding valve so that a medicine liquid is discharged through a gap on the outside. On the bottom wall of said bulging portion, a protrusion (94) for supporting said sliding valve is formed to form a gap on the bottom. The sliding valve (90) includes a body (101) having a smaller diameter than the inner diameter of said bulging portion and a supporting member (102) having a plurality of supporting protrusions protruding in a radial direction from the center of the body, arranged equidistantly in a circumferential direction and having a lower elastic modulus than that of said body, and said supporting protrusions are brought into contact with the inner face of said bulging portion. Since the cylinder is an integral type, intrusion of flowing water vapor and vacteria is prevented.

Dependencies are inferred from the claim text.