Abstract: A compound that exhibits excellent color tone stability and physical properties as well as excellent photopolymerization activity over a wide region from near-ultraviolet to visible region, permitting relaxed operation under ambient light, so that wide application can be found in the dental field and photopolymerization industry; and a relevant photopolymerization initiator and hardenable composition. In particular, there is provided a novel camphorquinone derivative having an acylphosphine oxide group [—(C?O)—(P?O)<] in each molecule. Further, there is provided a photopolymerization initiator comprising the camphorquinone derivative having an acrylphosphine oxide group [—(C?O)—(P?O)<] in each molecule as an indispensable component, loaded with at least one member selected from among a polymerization accelerator, a photoacid generator, a photosensitizer and a (bis)acylphosphine oxide, and provided a hardenable composition comprising the initiator.

Abstract: A compound that exhibits excellent color tone stability and physical properties as well as excellent photopolymerization activity over a wide region from near-ultraviolet to visible region, permitting relaxed operation under ambient light, so that wide application can be found in the dental field and photopolymerization industry; and a relevant photopolymerization initiator and hardenable composition. In particular, there is provided a novel camphorquinone derivative having an acylphosphine oxide group [—(C?O)—(P?O)<] in each molecule. Further, there is provided a photopolymerization initiator comprising the camphorquinone derivative having an acrylphosphine oxide group [—(C?O)—(P?O)<] in each molecule as an indispensable component, loaded with at least one member selected from among a polymerization accelerator, a photoacid generator, a photosensitizer and a (bis)acylphosphine oxide, and provided a hardenable composition comprising the initiator.

Abstract: The present invention provides a one-liquid curable composition comprising micro- and/or nano-capsules. More specifically, the present invention provides a one-liquid curable composition characterized in that a substance encapsulated within each micro- and/or nano-capsule and a substance enveloping said micro- and/or nano-capsule contain a combination of more than one material that can coexist with one another, selected arbitrary from radically-polymerizable monomers, polymerization initiators, polymerization accelerators, electrolyte polymers, electrolyte polymer solutions, hydroxycarboxylic acids, hydroxycarboxylic acid solutions, acid-reactive fillers, and acid-inactive fillers, and also characterized in that a wall material of said micro- and/or nano-capsule is an organic compound, and/or an inorganic compound, and/or an organic/inorganic complex compound.