| 摘要 |
<p>Air permeable, sterilising filter, partic. for the microphone of telephone handsets, is intended to remove the risk of bacterial infection from persons using the telephone. A cover of pliable, plastic material is placed over the microphone; it has a hole in the shape of a rose, (or of any other suitable design) which leaves a narrow margin around the periphery. Ribs or grids divided the hole into several separate openings. An impregnated porous sheet of a fine-textured material, such as glass fibre or a plastic foam, is fitted inside the cover and held in position by a retaining plate; it can be removed easily when the disinfectant has been exhausted by evaporation. The impregnating material consists of a mixture of alkyldimethylammonium chlorides of formula C6H5OH2N(CH3)RCl, where R is a mixture of C8H17 and C18H37. The filter is coated with a silicone film to prevent if from becoming fluffy and from a absorbing moisture from the atmosphere. A liquid perfume may be added to the mixture. The filter acts continuously and thoroughly sterilises the air and the breath for a long period.</p> |
