Abstract: A stable modified metal oxide sol which contains from 2 to 50 wt %, as calculated as metal oxides, of particles (c) comprising colloidal particles (a) of a metal oxide having primary particle diameters of from 2 to 60 nm, as nuclei, and a coating material (b) consisting of colloidal particles of an acidic oxide coated on the surface of the particles (a), and which has primary particle diameters of from 2 to 100 nm.

Abstract: A stable modified metal oxide sol which contains from 2 to 50 wt %, as calculated as metal oxides, of particles (c) comprising colloidal particles (a) of a metal oxide having primary particle diameters of from 2 to 60 nm, as nuclei, and a coating material (b) consisting of colloidal particles of an acidic oxide coated on the surface of the particles (a), and which has primary particle diameters of from 2 to 100 nm.

Abstract: A stable modified metal oxide sol which contains from 2 to 50 wt %, as calculated as metal oxides, of particles (c) comprising colloidal particles (a) of a metal oxide having primary particle diameters of from 2 to 60 nm, as nuclei, and a coating material (b) consisting of colloidal particles of an acidic oxide coated on the surface of the particles (a), and which has primary particle diameters of from 2 to 100 nm.

Abstract: The present invention provides a novel modified stannic oxide—zirconium oxide complex sol and a preparation method thereof, particularly a stable sol which contains 2-50% by weight of total metal oxides comprising modified colloidal particles of a stannic oxide—zirconium oxide complex having a particle diameter having 4.5-60 nm, wherein the particles are formed by coating complex colloidal particles of a stannic oxide—zirconium oxide having a bonded structure of stannic oxide colloidal particles and zirconium oxide colloidal particles at a ZrO2/SnO2 ratio of 0.02-1.0 based on weights of these oxides and having a particle diameter of 4-50 nm as nuclei, with colloidal particles of a tungsten oxide—stannic oxide—silicon dioxide complex having such a constitution that a WO3/SnO2 weight ratio is 0.1-100, that a SiO2/SnO2 weight ratio is 0.1-100 and having a particle diameter of 2-7 nm, and preparation method thereof.

Abstract: An optical element having, on an optical substrate, a cured film formed of a coating agent containing (A) modified stannic oxide-zirconium oxide composite colloid particles as prepared by coating at least a part of the surfaces of stannic oxide-zirconium oxide composite colloid particles with stannic oxide-tungsten oxide-silicon oxide composite colloid particles, and (B) an organosilicon compound.

Abstract: The present invention relates to a method for producing titanium oxide (TiO2)-tin oxide (SnO2) composite sol, a titanium oxide (TiO2)-zirconium oxide (ZrO2)-tin oxide (SnO2) composite sol, and a titanium oxide (TiO2)-cerium oxide (CeO2)-tin oxide (SnO2) composite sol. Further, the present invention relates to a coating composition containing any of the above-mentioned composite sols for forming coating films that are excellent in marring resistance, surface hardness, wearing resistance, transparency, heat resistance, light-resistant, weatherability, or water resistance on optical elements such as lenses for glasses and cameras, automotive windowpane, or optical filters attached to liquid-crystal displays, plasma displays, etc. and to optical elements having a cured film of the coating composition on the surfaces.

Abstract: A melamine.melam.melem salt of a polyphosphoric acid, which has a solubility of from 0.01 to 0.10 g/100 ml in water (25.degree. C.), a pH of from 4.0 to 7.0 as a 10 wt % aqueous slurry (25.degree. C.), and a melamine content of from 0.05 to 1.00 mol, a melam content of from 0.30 to 0.60 mol and a melem content of from 0.05 to 0.80 mol, per mol of the phosphorous atom; andA process for producing the above mentioned melamine.melam.melem salt of a polyphosphoric acid, which comprises the following steps (a) and (b):(a) a step of obtaining a reaction product by mixing melamine and phosphoric acid at a temperature of from 0 to 330.degree. C. in such a ratio that the melamine is from 2.0 to 4.0 mols per mol of the phosphoric acid (as calculated as orthophosphoric acid content), and(b) a step of baking the reaction product obtained in step (a) at a temperature of from 340 to 450.degree. C. for from 0.1 to 30 hours.

Abstract: A 1,3,5-triazine derivative salt of a polyacid comprising phosphorus, sulfur and oxygen, which has a solubility of from 0.01 to 0.10 g/100 ml in water (25.degree. C.) and a pH of from 2.0 to 7.0 as a 10 wt % aqueous slurry (25.degree. C.), and which is obtained from the following steps (a) and (b):(a) a step of obtaining a reaction product by mixing melamine, phosphoric acid and sulfuric acid at a temperature of from 0 to 330.degree. C. in such ratios that the melamine is from 1.0 to 4.0 mols per mol of the total molar amount of the phosphoric acid (as calculated as orthophosphoric acid content) and the sulfuric acid (as sulfuric acid content), and the sulfuric acid (as sulfuric acid content) is from 0.05 to 20 mols per mol of the phosphoric acid (as calculated as orthophosphoric acid content), and(b) a step of baking the reaction product obtained in step (a) at a temperature of from 340 to 400.degree. C. for from 0.1 to 30 hours; and a process for its production.

Abstract: A sol having dispersed in a liquid medium particles of a hydrated zinc stannate having a primary particle diameter of from 2 to 200 nm and represented by the formula xZnO.multidot.ySnO.sub.2 .multidot.zH.sub.2 O wherein the molar ratio of x:y:z is 1:0.83 to 1.43:1.00 to 5.00.

Abstract: A sol having dispersed in a liquid medium particles of a hydrated zinc stannate having a primary particle diameter of from 2 to 200 nm and represented by the formula xZnO.ySnO.sub.2.zH.sub.2 O wherein the molar ratio of x:y:z is 1:0.83 to 1.43:1.00 to 5.00.

Abstract: A sol having dispersed in a liquid medium particles of a hydrated zinc stannate having a primary particle diameter of from 2 to 200 nm and represented by the formula xZnO.ySnO.sub.2.zH.sub.2 O wherein the molar ratio of x:y:z is 1:0.83 to 1.43:1.00 to 5.00.

Abstract: A sol comprising colloidal particles of sodium magnesium fluoride (NaF.MgF.sub.2) having an average particle diameter of from 10 to 100 nm.

Abstract: An electro-conductive oxide particle comprising indium atoms, antimony atoms and oxygen atoms in a molar ratio of In:Sb:O being 1:0.02-1.25:1.55-4.63 and having a primary particle diameter of from 5 to 500 nm.

Abstract: An electro-conductive oxide particle comprising indium atoms, antimony atoms and oxygen atoms in a molar ratio of In:Sb:O being 1:0.02-1.25:1.55-4.63 and having a primary particle diameter of from 5 to 500 nm.

Abstract: A sol comprising colloidal particles of sodium magnesium fluoride (NaF.MgF.sub.2) having an average particle diameter of from 10 to 100 nm.

Abstract: An electro-conductive oxide particle comprising indium atoms, antimony atoms and oxygen atoms in a molar ratio of In:Sb:O being 1:0.02-1.25:1.55-4.63 and having a primary particle diameter of from 5 to 500 nm.

Abstract: A sol comprising colloidal particles of sodium magnesium fluoride (NaF.MgF.sub.2) having an average particle diameter of from 10 to 100 nm.