| 摘要 |
PROBLEM TO BE SOLVED: To prevent leakage of ink even when the ink touches a vent for a long time by employing a porous film having a specified mean bore size or less and a specified air permeability or below expressed in terms of Gurley number as a filter. SOLUTION: A cap 12 is provided with a vent 14 through which the inner space of a case 1 communicates with the outer space. The vent 14 is fixed with a filter 13 and the inner space of the case 1 communicates with the outer space through the filter 13. The filter 13 is made of a fluororesin film of having mean bore size of 0.5μm or less and a Gurley number of 60 see/100 ml or below. According to the structure, leakage of ink can be prevented even when ink 2 touches the vent 14 for a long time. The porous film is preferably made of fluororesin, e.g. tetrafluoroethylene-ethylene copolymer. |
