| 摘要 |
PURPOSE:To provide alkali resistance to ink and to make liquid tightness good, by a method wherein the material of a rubber stopper is fluororubber as base polymer, into which fluororubber of a low molecular weight is blended. CONSTITUTION:For the material of this rubber stopper 33, fluororubber is used as base polymer; the hardness of rubber is made about 35 deg.C-40 deg. by blending liquid low-molecular-weight fluororubber thereinto. Further, when a hollow needle 35 is pulled out in the case of 45 deg. level in rubber hardness at a low temperature of 0 deg.C, the rubber stopper 33 is not immediately closed but ink 27 leaches. The hardness of rubber should preferably be 40 deg. level. That is, for the hardness of rubber, softness like that of fluorosilicone and silicone rubber level is required. Because the rubber hardness of the rubber stopper 33 is decreased from a standpoint of quality, the hollow needle 35 is easily thrusted, and further, its sealing is good when it is extracted. Furthermore, because the material of the rubber stopper 33 is fluororubber having alkali resistance, there is also no problem concerning deterioration due to ink 27. |
