| 摘要 |
<p>PURPOSE:To improve the transparency at a broad wavelength range, the durability and the mechanical strength of the titled body by using a polyvinyl isobutyral which is specified the content and the degree of acetalization of a vinylacetate component, as a transparent thin film. CONSTITUTION:The thin film of polyvinyl isobutyral which contains <=10mol.% the vinyl acetate component and has >=60mol.% the degree of acetalization, is used in a transparent thin film type cover body which is provided away from the surface of a substrate at the prescribed distance. The thin film of the protective dust proof body is formed by a method in which the polyvinyl isobutyral is dissolved to an appropriate volatile solvent such as ethanol, methylene chloride and acetone, and the obtd. solution is flowed and spreaded on the smooth substrate such as a silicon wafer, a glass plate and a metal plate, thereafter evaporating the solvent, etc. The mean mol.wt. of the polyvinyl isobutyral is preferably a range of 10,000-200,000. Thus, the titled body having the remarkably improved transparency at the broad wavelength range from a near UV ray to a far UV ray and the improved mechanical property is obtd.</p> |
