Abstract: An epoxy resin composition according to the present invention is one initiating cationic polymerization upon irradiation with energy rays. The epoxy resin composition is formed of at least bisphenol type epoxy resin (A) as an active ingredient, epoxy resin (B) shown in the following formula and cationic polymerization catalyst (C). The epoxy resin composition can improve the thermal resistance of the adhesive layer in an optical information recording medium, and the adhesive property of the adhesive layer is not lowered even if its hardness is increased or it is in high humidity.

Abstract: The present invention aims to provide a resin suitable for use as a protective layer or adhesive layer formed on the surface of a metal film. A liquid oligomer having a high specific gravity of 1.10 or more is contained in a photocurable resin involved in photopolymerization of a resin composition. Upon application on a metal film 12 and photopolymerization, bulky substituents owned by the high-specific gravity liquid oligomer prevent penetration of moisture to provide a protective film 13 with low water permeability. Said high-specific gravity liquid oligomer should desirably be contained in the photocurable resin within the range from 35% by weight to 78% by weight both inclusive.

Abstract: The present invention provides a protective film with high mechanical strength free from dust. A protective film 14 of an optical recording medium 2 is formed by applying and curing a composition for protective films obtained by dispersing in a curable binder material a first lubricant compatible with said binder material and a second lubricant incompatible with said binder material but compatible with said first lubricant. The incompatible second lubricant is stably and homogeneously dispersed to enhance lubricity and slidability while any excessive amount of the lubricant does not deposit on the surface of the protective film. The binder material is desirably photocurable.

Abstract: An epoxy resin composition according to the present invention is one initiating cationic polymerization upon irradiation with energy rays. The epoxy resin composition is formed of at least bisphenol epoxy resin (A) as an active ingredient, epoxy resin (B) shown in the following formula and cationic polymerization catalyst (C).

Abstract: An ultraviolet curing resin for an optical disk according to the present invention which includes: a multiacrylate-functional monomer selected from the group consisting of multiacrylate-functional monomers and multimethacrylate-functional monomers and mixtures of the foregoing monomers; a difunctional monomer selected from the group consisting of diacrylate-functional monomers, dimethacrylate-functional monomers and mixtures of the foregoing monomers; a diluent; an adhesion promoter; and a photopolymerization initiator. The ultraviolet curing resin may also include a surface tension adjusting agent.