Abstract: It is an object of the present invention to provide an adhesive for sealing an organic electroluminescence device, an adhesive tape for sealing an organic electroluminescence device, a double-faced adhesive tape for sealing an organic electroluminescence device, a method of sealing an organic electroluminescence device and an organic electroluminescence device, which can seal an organic electroluminescence device without degrading it with light or heat. The present invention relates to an adhesive for sealing an organic electroluminescence device, which comprises a photo cationic polymerizable adhesive containing a photo cationic polymerizable compound and a photo cationic polymerization initiator and, initiating a curing reaction by light irradiation and proceeding the curing reaction by a dark reaction even after interrupting the light irradiation.

Abstract: It is an object of the invention to provide a polyvinyl acetal resin for lacquer and ink, which can suppress the occurrence of coloring and foul odor of the polyvinyl acetal resin itself even when no antioxidant is used at all therein, and a lacquer and ink composition which has excellent color and the high stability of viscosity in storing it for long periods. The invention provides a polyvinyl acetal resin for lacquer and ink synthesized by acetalization reactio of polyvinyl alcohol and an aldehyde, wherein a polymerization degree is 100 to 3,000, a proportion of a residual acetyl group is 25 mol % or less and a proportion of a residual hydroxyl group is 17 to 35 mol %; a content of the residual aldehyde is 100 ppm or less, a content of residual butyric acid is 100 ppm or less, a content of residual 2-ethyl-2-hexenal is 100 ppm, and a content of a residual acid catalyst is 300 ppm or less, and no antioxidant is remained at all therein.

Abstract: It is an object of the invention to provide a polyvinyl acetal resin for lacquer and ink, which can suppress the occurrence of coloring and a foul odor of the polyvinyl acetal resin itself even when no antioxidant is used at all therein, and a lacquer and ink composition which has excellent color and the high stability of viscosity in storing it for long periods.