| 摘要 |
A device for giving a visual indication of the amount of residual ethylene oxide present in ethylene oxide treated solid hospital articles and other health devices. The amount of residual ethylene oxide is indicated by the difference in color exhibited by different sensitized areas of the device in the form of an opaque dark colored support member having bonded to its surface a thin film of a cholesteric liquid crystal composition in a solid film-forming binder. The film is made by laying down on the surface of the support member a solution or dispersion of liquid crystals which exhibits a change in color when in contact with ethylene oxide at a temperature from 60 DEG to 100 DEG F. in a solution of the solid binder, then evaporating the solvent. As prepared, the film is in a form adapted to be packaged with goods to be subjected to sterilization with ethylene oxide, a portion of the film being sealed within a transparent enclosure the walls of which possess a permeability to ethylene oxide no greater than that of the material of the treated goods.
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