Abstract: Disclosed herein is method for producing an iron dinuclear complex having two iron atoms bonded to each other via one oxygen atom and a ligand structure containing a Schiff base, a method which can produce an ester compound in high yield by the transesterification of an alcohol compound with a carboxylate ester even in the case where the raw material alcohol has a tertiary hydroxyl group which is usually difficult to esterify by transesterification, and a method which can produce a wholly esterified compound by transesterification catalyzed by an iron complex.

Abstract: Disclosed herein is method for producing an iron dinuclear complex having two iron atoms bonded to each other via one oxygen atom and a ligand structure containing a Schiff base, a method which can produce an ester compound in high yield by the transesterification of an alcohol compound with a carboxylate ester even in the case where the raw material alcohol has a tertiary hydroxyl group which is usually difficult to esterify by transesterification, and a method which can produce a wholly esterified compound by transesterification catalyzed by an iron complex.

Abstract: An object of the invention is to provide a method for producing a (meth)acrylate ester compound by the transesterification of an alkyl (meth)acrylate with an alcohol compound having a tertiary hydroxyl group so as to esterify all the hydroxyl groups present in the alcohol compound with a high yield or, in a preferred embodiment, a method for esterifying a polyhydric alcohol compound having a tertiary hydroxyl group and also having a primary hydroxyl group and/or a secondary hydroxyl group by one-pot transesterification into a (meth)acrylate ester compound of the polyhydric alcohol. The method for producing a (meth)acrylate ester compound includes a step (I) of transesterifying an alkyl (meth)acrylate with an alcohol compound having a tertiary hydroxyl group using a transesterification catalyst including a complex of iron with a specific ligand, the water content in the transesterification reaction system being not more than 1000 ppm.

Abstract: The present invention provides a dental mill blank having excellent mechanical strength and having gloss retention high enough to maintain the gloss similar to that of natural teeth in an oral cavity for a long period of time. The present invention is a dental mill blank made of a cured product of a curable composition containing: a polymerizable monomer (A); and a spherical inorganic filler (B) having an average primary particle size of not less than 0.1 ?m and less than 1 ?m.

Abstract: The present invention provides a dental mill blank having excellent mechanical strength and having gloss retention high enough to maintain the gloss similar to that of natural teeth in an oral cavity for a long period of time. The present invention is a dental mill blank made of a cured product of a curable composition containing: a polymerizable monomer (A); and a spherical inorganic filler (B) having an average primary particle size of not less than 0.1 ?m and less than 1 ?m.

Abstract: The present invention provides a dental curable composition exhibiting both excellent light diffusion and excellent transparency, and having high mechanical strength and surface smoothness and gloss after polishing as a cured product as well as good handling properties as a paste. The present invention is a dental curable composition including: a polymerizable monomer (A) having a refractive index of 1.52 to 1.58 after polymerization; inorganic particles (B) having a refractive index of 1.43 to 1.50; and inorganic particles (C) having a refractive index of 1.52 to 1.58. The inorganic particles (B) are aggregates of inorganic fine particles having an average primary particle size of 2 to 50 nm, and the content of the inorganic particles (B) is 0.1 to 10% by weight.

Abstract: A dental composition of the present invention includes: a polymerizable monomer (A); an amorphous filler (B) having an average particle size of 1 to 20 ?m and including silica-based fine particles and coatings of an oxide that cover the surfaces of the silica-based fine particles; and inorganic particles (C) having an average particle size of 0.1 to 1.0 ?m. The oxide contains a zirconium atom, a silicon atom, and an oxygen atom. It is preferable that the dental composition contain 50 to 400 parts by weight of the filler (B) and 100 to 400 parts by weight of the inorganic particles (C) per 100 parts by weight of the polymerizable monomer (A).

Abstract: The present invention provides a dental composition exhibiting both an excellent light diffusion property and excellent transparency, and having high mechanical strength and surface smoothness and gloss after polishing as a cured product and good handling properties as a paste. The present invention is a dental composition including: a polymerizable monomer (A); and an amorphous powder (B). The amorphous powder (B) has an average particle size of 1 to 20 ?m, and includes silica-based fine particles and coatings of an oxide that cover the surfaces of the silica-based fine particles. The oxide contains a zirconium atom, a silicon atom, and an oxygen atom. The difference in refractive index between the cured product of the polymerizable monomer (A) and the amorphous powder (B) is 0.005 to 0.03.

Abstract: The present invention provides a dental curable composition exhibiting both excellent light diffusion and excellent transparency, and having high mechanical strength and surface smoothness and gloss after polishing as a cured product as well as good handling properties as a paste. The present invention is a dental curable composition including: a polymerizable monomer (A) having a refractive index of 1.52 to 1.58 after polymerization; inorganic particles (B) having a refractive index of 1.43 to 1.50; and inorganic particles (C) having a refractive index of 1.52 to 1.58. The inorganic particles (B) are aggregates of inorganic fine particles having an average primary particle size of 2 to 50 nm, and the content of the inorganic particles (B) is 0.1 to 10% by weight.

Abstract: A dental composition of the present invention includes: a polymerizable monomer (A); an amorphous filler (B) having an average particle size of 1 to 20 ?m and including silica-based fine particles and coatings of an oxide that cover the surfaces of the silica-based fine particles; and inorganic particles (C) having an average particle size of 0.1 to 1.0 ?m. The oxide contains a zirconium atom, a silicon atom, and an oxygen atom. It is preferable that the dental composition contain 50 to 400 parts by weight of the filler (B) and 100 to 400 parts by weight of the inorganic particles (C) per 100 parts by weight of the polymerizable monomer (A).

Abstract: The present invention provides a dental composition exhibiting both an excellent light diffusion property and excellent transparency, and having high mechanical strength and surface smoothness and gloss after polishing as a cured product and good handling properties as a paste. The present invention is a dental composition including: a polymerizable monomer (A); and an amorphous powder (B). The amorphous powder (B) has an average particle size of 1 to 20 ?m, and includes silica-based fine particles and coatings of an oxide that cover the surfaces of the silica-based fine particles. The oxide contains a zirconium atom, a silicon atom, and an oxygen atom. The difference in refractive index between the cured product of the polymerizable monomer (A) and the amorphous powder (B) is 0.005 to 0.03.

Abstract: A novel hydrophobic vitamin B.sub.12 derivative represented by the formula: ##STR1## wherein R represents an alkyl group having 2 to 17 carbon atoms, and X represents a cyano group, a hydroxyl group, an alkyl group or a 5'-deoxyadenosyl group. Since the derivative is hydrophobic, it can be taken up by an organism by thermodynamic diffusion, a passive transport, without an active transport.