| 摘要 |
PROBLEM TO BE SOLVED: To eliminate adsorption of an active principle of injection and maintain sliding performance of a gasket or the like by a method wherein an internal wall surface of an outer cylinder is made of a polyolefin resin and the internal wall surface where the gasket slides undergoes a hydrophilic treatment so as to have a specified angle of contact. SOLUTION: An injector 1 is so arranged to previously house an injection 3 in an outer cylinder 2 and the outer cylinder 2 is made up of a cylinder 2A, a needle mounting port member 2B and a finger hook member 2C. The internal wall surface 4 of the cylinder member 2A is made of a polyolefin based resin and the internal wall surface 4 where a gasket 5 slides undergoes a hydrophilic treatment to make the angle θ of contact (H2 O at 25 deg.) up to 90 deg.. The hydrophilic treatment herein used is plasma treatment or ozone treatment or a graft polymerization treatment using a monomer containing a hydrophilic group together with the plasma treatment or the ozone treatment. The monomer containing a hydrophilic group is a N-based heterocyclic monomer, an acrylic based monomer or vinyl ether. |
