| 摘要 |
PURPOSE:To provide a thin resin film with a uniform thickness, excellent in durability and transmittance to rays in far ultraviolet regions, useful for a dust hood in print and exposure units, etc., by dissolving a particular cyanoethylcellulose derivative in a volatile solvent to provide a film by flow casting, etc. CONSTITUTION:A cyanoethylcellulose derivative with a degree of polymn. of 50-1500 having a cyanoethyl group and, if necessary, substituents with the cotal degree of substitution of 2.0-3.0 such as 1-5C alkyl, 1-10C acyl, 1-4C hydroxyalkyl, or 1-20C perfluoroacyl having a degree of substitution of 1.0 or below, respectively, dissolved in a volatile solvent such as acetone or cyclo hexane is formed into film by flow casting, etc., thus yielding a a thin resin film comprising a cyanoethylcellulose derivative having a uniform thickness within a range of 0.5-10mum and a transmittance in wavelengths of 350-500nm of 88% or more and that of 250-350nm of 80% or more. |
