Abstract: An ultraviolet-curable adhesive having an excellent moisture resistance and suitable for bonding optical disks having an information recording layer (vapor deposition layer), particularly optical disks having a thick vapor deposition layer, which contains, as essential components, (A) N-vinylpyrrolidone, (B) a urethane (meth)acrylate oligomer derived from a caprolactone-based polyol, an alicyclic diisocyanate and (meth)acrylic acid, and (C) a photopolymerization initiator containing (C-1) a photopolymerization initiator composed of only a carbon atom, a hydrogen atom and an oxygen atom without containing a nitrogen atom, a sulfur atom and a phosphorus atom and (C-2) a photopolymerization initiator containing a nitrogen atom and/or a sulfur atom in a (C-1)/(C-2) ratio of 70/30 to 100/0 by weight.

Abstract: An adhesive composition including (a) a polymerizable (meth)acrylate compound having a phosphate group, (b) a thiol compound, (c) a polymerizable compound having a double bond and having no phosphate group, and (d) a photopolymerization initiator. The adhesive composition is suitably used for fabrication of optical discs.

Abstract: The disclosed organo-polysiloxane derivative is useful as a dispersing agent for homogeneously dispersing a silicone gel in a curable resin such as an epoxy resin. The organo-polysiloxane derivative is prepared by first reacting an organo-polysiloxane compound A having an active hydrogen-containing group in each of its both terminals and having from 5 to 70 siloxane bonds with a bifunctional organic compound B having two functional groups reactable with active hydrogen. The reaction mixture obtained in the first reaction is reacted with a mixture of a bifunctional organic compound C having two active hydrogens and a bifunctional organic compound D having two functional groups reactable with the active hydrogen.