1. Field of the Invention
The present invention relates to an airtight cap structure with a use end portion detachably covered by a cap to prevent drying out of the use end portion of a writing tool, cosmetics, and the like.
2. Description of the Related Art
Heretofore, as a cap structure of this type, for example, the cap structure as disclosed in Japanese Patent Laid-Open No. 9-30187 has been known. The cap structure disclosed in this patent publication is a cap structure for a low viscosity ink writing tool, and the cap comprises an outer cap and a cupped sealing body which is fixed inside the outer cap and comprised of an elastic material. When the cap is attached a free end peripheral edge portion of the sealing body is allowed to be appressed to a tip end surface of a shaft barrel.