| 摘要 |
PURPOSE:To realize a blade having high press contact force and low permanent strain by incorporating a trifunctional polyol having a large mol.wt. together with a bifunctional polyol into the molecular main chain in part of the polyol components of a polyurethane. CONSTITUTION:The cleaning blade is formed by curing the urethane prepolymer contg. 25-5wt% trifunctional polyol together with 75-95wt% bifunctional polyol having 600-3,000mol.wt. in the molecular main chain as the polyol component and contg. 4-10wt% isocyanate group by a curing agent. This urethane prepolymer is brought into reaction for 10-180min at 70-150 deg.C by the conventional method and is then molded by an injection molding method, etc., to the cleaning blade. The blade which has the high press contact force and the extremely low permanent strain while maintaining the various characteristics required for the blade is thus realized. |
