US Patent 9669973 Double-walled container

Double container includes: inner layer body provided with upper opening; outer layer body accommodating inner layer body and including mouth portion provided with aperture; and dispensing cap provided with content dispensing spout and fitted to mouth portion. Double container further includes: inside plug provided with dispensing passage and fitted to upper opening; and check valve configured to open and close dispensing passage. Dispensing cap has a cylindrical wall, and cylindrical wall has a lower end portion fitted to an outer circumferential surface of outer layer body to provide vent region inside dispensing cap. Throttle passage is provided in a passage extending from ambient air introducing hole through vent region to aperture.