PURPOSE: To prevent poor performance of light emission due to layer exfoliation under manufacturing processes or during service and provide a stable light emission characteristics by using a composite of cyanoethyl pullulan and cyanoethylated compound of a substance having hydroxyl radicals which are selected from saccharodes, sugar alcohols, multi-valent alcohols having a molecular weight under a specific value, and derivative therefrom.
CONSTITUTION: Cyanoethly pullulan as No.1 component shall preferably have a cyanoethyl radical substitution factor of no less than 80%. Examples of the cyanoethylated compound as No.2 component consisting of a substance having at least one sort of hydroxyl radical selected from minor saccharides, sugar alcohols, multi-valent alcohols having a molecular weight under 300, and derivative therefrom are cyanoethyl glucose, cyanoethyl sorbitol, etc. The cyanoethylated compound is obtained by subjecting the applicable ones of these minor saccharides, sugar alcohols, and multi-valent alcohols to reaction with acrylonitrile according to conventional process, wherein the substitution factor of cyanoethyl radicals shall preferably be no less than 80%. The cyanoethylated compound synthesized from materials having a molecular weight under 300 gives a dielectric coefficient as high as over 35 at normal temp. The preferable content of this cyanoethylated compound is 5-50%.
FUKUI IKUO
MARUYAMA KAZUMASA
