| 摘要 |
PURPOSE:To obtain a composition which is effective for sealing of a light emitting element such as LED, etc., by adding an adequate amount of a cross-linking agent or a photosensitizing agent, multifunctional cross-linking assistant agent, vinyl monomer, silane coupling agent, etc., to a copolymer of ethylene-vinyl acetate. CONSTITUTION:A copolymer resin of ethylene-vinyl acetate (EVA) to be used contains vinyl-acetate of 5 to 50% or preferably of 15 to 40%. Moreover, an organic peroxide is suitable as the cross-linking agent for the heated cross- linking. Peroxide is used independently or mixingly and 5 pts.wt. is usually sufficient for EVA of 100 pts.wt. As the photosensitizing agent to be used, for example, benzoin, benziphenone may be usually used independently or mixingly in 0.05 to 10 pts.wt. or preferably in 0.1 to 5 pts.wt. for EVA of 100 pts.wt. The composition for sealing is mixed with EVA and additive agents explained above and is then kneaded by an injection machine or roller and thereafter these materials are formed into a film of the predetermined shape by the filming methods such as calender, roll, T die injection and inflation, etc. |
