Abstract: The present invention provides dental fillers having the optical and/or mechanical characteristics required to dental materials, a method of producing the same, and a dental composite material prepared with use of the dental filler. More specifically, the present invention provides a dental filler containing a zirconium silicate compound, especially a zirconium trisilicate compound with a wadeite type crystalline structure and having an average particle diameter in the range from 2 to 50,000 nm, a method of producing the same, a dental composite material containing the dental filler and a hardenable resin selected from an acrylic resin, a methacrylic resin, an epoxy resin, a vinyl resin, a urethane resin and the like.

Abstract: The hard coat layer-forming composition of this invention includes (A) composite oxide fine particles with a mean particle diameter of 1 to 200 nm, containing titanium, tin and optionally silicon, and with a rutile-type crystal structure, (B) an organosilicon compound represented by the formula R1aR2bSi(OR3)4?(a+b) and/or a hydrolyzate thereof, and (C) a cyanamide derivative compound. A hard coat layer formed from the composition not only is excellent in transparency, scratch resistance, adhesion property, weathering resistance, impact resistance, etc. but also can enjoy no coloration or little coloration, particularly in bluing or yellowing, upon exposure to or irradiation with ultraviolet rays, even if an antireflection film is provided.

Abstract: The hard coat layer-forming composition of this invention includes (A) composite oxide fine particles with a mean particle diameter of 1 to 200 nm, containing titanium, tin and optionally silicon, and with a rutile-type crystal structure, (B) an organosilicon compound represented by the formula R1aR2bSi(OR3)4?(a+b) and/or a hydrolyzate thereof, and (C) a cyanamide derivative compound. A hard coat layer formed from the composition not only is excellent in transparency, scratch resistance, adhesion property, weathering resistance, impact resistance, etc. but also can enjoy no coloration or little coloration, particularly in bluing or yellowing, upon exposure to or irradiation with ultraviolet rays, even if an antireflection film is provided.

Abstract: The present invention provides dental fillers having the optical and/or mechanical characteristics required to dental materials, a method of producing the same, and a dental composite material prepared with use of the dental filler. More specifically, the present invention provides a dental filler containing a zirconium silicate compound, especially a zirconium trisilicate compound with a wadeite type crystalline structure and having an average particle diameter in the range from 2 to 50,000 nm, a method of producing the same, a dental composite material containing the dental filler and a hardenable resin selected from an acrylic resin, a methacrylic resin, an epoxy resin, a vinyl resin, a urethane resin and the like.

Abstract: A composite polymer is obtained by reacting (a) an elastomer having a carboxyl group with (b) metal oxide fine particles each having an epoxy ring-containing group on the particle surface. A thermally cured product of the composite polymer is a material favorable for forming a primer layer which has not only high transparency but also excellent adhesion to a hard coat layer and is excellent also in scratch resistance, heat resistance, weathering resistance, dyeing property, impact resistance and the like. An article such as an optical article whose primer layer comprises the thermally cured product of the composite polymer has high transparency and is excellent also in heat resistance.

Abstract: A hard coat or a transparent film having excellent adhesion to a polycarbonate substrate is provided. The transparent film-forming coating liquid of the present invention comprises the following components (A) to (D): (A) an organosilicon compound and/or a hydrolyzate of the organosilicon compound, (B) metal oxide fine particles each of which comprises a metal oxide core particle and a coating layer composed of antimony oxide, (C) one or more curing agents (curing agent (A)) selected from the group consisting of a polythiol compound, an organic polycarboxylic acid and an acetylacetone metal complex, and (D) a curing agent (curing agent B) comprising a compound containing basic nitrogen. The metal oxide particles (B) have been surface-modified with an organosilicon compound or an amine compound.