| 摘要 |
PURPOSE:To protect a precision polished surface against deliquescence by the moisture in outdoor air by coating a thin film consisting of a high-polymer material on the precision polished crystal surface of an IR transmittable material constituting an IR transmittable element. CONSTITUTION:The high-polymer material having relatively weak absorption intensity in an IR wavelength region, for example, polymethyl methacrylate of the like is dissolved in an org. solvent, for example, chloroform, etc. On the other hand, the crystal of the precision polished IR transmittable material such as KBr is dipped in a soln. of an org. solvent having high purity, for example, chloroform and the residue of polishing is washed away by high-frequency ultrasonic cleaning, etc. The crystal of the IR transmittable material is then dipped in the dil. soln. of the high-polymer material and when the crystal is thereafter dried at a room temp., the extremely thin film of the high-polymer material is formed on the prescribed polished surface of the crystal. The thin film of the high-polymer material formed in such a manner shuts off thoroughly the polished surface from the moisture in the outdoor air and does not contain pinholes at all. |
