Abstract: The invention provides a cation polymerizable resin composition excellent in curing properties and corrosion resistance with less resin coloration and less cure shrinkage, which is a material suitable as a surface protective material for optical disk. Specifically, the cation polymerizable resin composition comprises an epoxy compound (A) as an essential ingredient represented by formula 1 wherein R1 and R2 each represent a saturated or unsaturated carbon atom, and R3 represents a hydrogen atom or a saturated or unsaturated carbon atom, a cation polymerizable compound (B) other than the epoxy compound represented by formula 1, a photo cation polymerization initiator (C) and a photo radical polymerization initiator (D).

Abstract: A photocurable resin composition comprises a cationic polymerizable compound (A), an acrylic resin (B) and a cationic photopolymerization initiator (C), in which the acrylic resin (B) has a cationic polymerizable functional group, and the content of the component (A) is 30 to 95 parts by mass and the content of the component (B) is 5 to 70 parts by mass, based on 100 parts by mass of the total amount of the components (A) and (B). In addition, the functional group of the acrylic resin (B) preferably contains at least one of a cyclic ether group, a vinyloxy group, an acid adduct of a vinyloxy group, and an active hydrogen group, with the active hydrogen group preferably being a hydroxyl group. The photocurable resin composition has sufficient curability and sufficient adhesiveness to rigid plastics such as polycarbonate and PET having poor adhesive property.

Abstract: The invention provides a cation polymerizable resin composition excellent in curing properties and corrosion resistance with less resin coloration and less cure shrinkage, which is a material suitable as a surface protective material for optical disk.

Abstract: A photocurable resin composition comprises a cationic polymerizable compound (A), an acrylic resin (B) and a cationic photopolymerization initiator (C), in which the acrylic resin (B) has a cationic polymerizable functional group, and the content of the component (A) is 30 to 95 parts by mass and the content of the component (B) is 5 to 70 parts by mass, based on 100 parts by mass of the total amount of the components (A) and (B). In addition, the functional group of the acrylic resin (B) preferably contains at least one of a cyclic ether group, a vinyloxy group, an acid adduct of a vinyloxy group, and an active hydrogen group, with the active hydrogen group preferably being a hydroxyl group. The photocurable resin composition has sufficient curability and sufficient adhesiveness to rigid plastics such as polycarbonate and PET having poor adhesive property.

Abstract: There is disclosed an optical recording medium including a recording layer, one or more intermediate layers, and a printable or typable surface protective layer disposed in this order on a transparent substrate having an annular plate shape, the optical recording medium having an inner peripheral portion in which the recording layer is not formed on an inner peripheral side in a radial direction of the transparent substrate, wherein the surface protective layer is formed in at least a part of the inner peripheral portion, and a hydrophobic intermediate layer is directly formed on the transparent substrate in a region of the inner peripheral portion in which the surface protective layer is formed. Label information can be formed on the optical recording medium even in an innermost peripheral hub portion by printing or the like.

Abstract: Provided is an optical recording medium comprising at least a recording layer, a metal reflective layer, a protective layer and a printing layer laminated on a transparent substrate, wherein the printing layer is obtained by curing a UV-curing ink composition and said ink composition contains a compound which has a solubility parameter falling in the range of 7 to 10 and which takes no part in UV curing and does not react with other components contained therein.

Abstract: Ferromagnetic metal particles the surface layer of which comprises laminatedly covered films of a ferrite compound having a spinel structure of at least one metal selected from cobalt, zinc, manganese, aluminum, chromium, nickel and copper and iron and a preparation process thereof.The particles can be used as a high density magnetic recording medium.