Mold for gasket for prefilled syringe

Abstract

The present invention aims to provide a gasket for a pre-filled syringe which has excellent air-tightness and liquid-tightness and a mold for forming the gasket. The present invention relate to a mold for a gasket laminated with an inactive film for a pre-filled syringe, wherein at least a surface of the mold which forms a seal sliding surface of an annular protrusion of the gasket is mirror finished to have an arithmetic mean roughness Ra of less than 0.03 μm.

1 . A mold for a gasket laminated with an inactive film for a pre-filled syringe,
 wherein at least a surface of the mold which forms a seal sliding surface of an annular protrusion of the gasket is mirror finished to have an arithmetic mean roughness Ra of less than 0.03 μm.   
     
     
         2 . The mold for a gasket for a pre-filled syringe according to  claim 1 ,
 wherein the mirror finishing is mirror polishing using an abrasive made of alumina or diamond.   
     
     
         3 . The mold for a gasket for a pre-filled syringe according to  claim 1 ,
 wherein the mold is made of a stainless steel mold material or a plated stainless steel mold material with a plating thickness of not more than 15 μm.   
     
     
         4 . The mold for a gasket for a pre-filled syringe according to  claim 1 ,
 wherein the inactive film is a 20 to 200 μm-thick film of polytetrafluoroethylene, ethylene tetrafluoroethylene copolymer, or ultra-high molecular weight polyethylene, formed by skiving, inflation, or extrusion.   
     
     
         5 . A gasket laminated with an inactive film for a pre-filled syringe, which is produced by molding at 155° C. to 200° C. using the mold according to  claim 1 .