Abstract: An organic phosphate compound having at least one radically polymerizable double bond, at least one phosphate residue having one or two hydroxyl groups, and at least one hydrocarbon group having 4 or more carbon atoms in a molecule, wherein a 10% by weight methanol solution of the organic phosphate compound has an electric conductivity at 25° C. of 0.5 mS/cm or less, and/or the organic phosphate compound has a light transmittance at 455 nm of 90% or more; a process for preparing the organic phosphate compound; a dental polymerizable composition comprising (a) the organic phosphate compound and (b) a polymerizable monomer capable of copolymerizing with the organic phosphate compound.

Abstract: A polymerizable composition for dental use, containing monomer (a) with a polymerizable olefinic unsaturated group, acylphosphine oxide (b), organic peroxide (c), tertiary amine (d) and aromatic sulfinic acid and/or a salt thereof (e). The polymerizable composition for dental use exerts excellent curability by any of photo-polymerization and chemical polymerization, having a good color for dental use, with less color change between prior to and after polymerization, and excellent light resistance, producing a cured product with a smaller thickness of the unpolymerized layer on the surface, having larger curing depth and excellent adhesion to teeth and metals and the like and great color fastness in hot water and in darkness. By taking advantages of these excellent properties, the polymerizable composition can effectively be used for utilities, for example as a bonding agent, a composite resin, an adhesive agent, a primer and an opaque primer and the like, for dental use.