摘要:
The present invention provides a method for producing a material dispersed with ultraviolet shielding fine particles, characterized by subjecting a starting material liquid mixture comprising particles comprising one or more inorganic substances having shielding abilities against ultraviolet light, one or more silicone dispersants selected from modified silicones and reactive silicones, and a silicone oil to a mill treatment and/or a high-pressure dispersion treatment; and ultraviolet shielding fine particles or a material dispersed therewith, characterized by being produced by the above method. Also, the present invention provides a method of producing a powdery product of ultraviolet shielding fine particles, characterized by drying the material dispersed with ultraviolet shielding fine particles obtainable by the above method. Further, the present invention provides cosmetics comprising a material dispersed with ultraviolet shielding fine particles or a powdery product of the ultraviolet shielding fine particles. The material dispersed with ultraviolet shielding fine particles of the present invention is characterized in that the ultraviolet shielding fine particles comprise particles comprising one or more inorganic substances having shielding abilities against ultraviolet light, surfaces thereof being coated with one or more silicone dispersants selected from modified silicones and reactive silicones, and that at least a part of the ultraviolet shielding fine particles is dispersed in a silicone oil as aggregated particles of the particles comprising inorganic substances.
摘要:
The present invention is directed to ultraviolet shielding composite fine particles having transparency in a visible light region, comprising (a) matrix particles comprising an aggregate of primary particles having an average particles diameter of from 0.001 to 0.3 .mu.m, said aggregate being formed while retaining the shapes of the primary particles; and (b) daughter particles having an average particle diameter of from 0.001 to 0.1 .mu.m, said daughter particles being dispersed in and supported by said matrix particles, wherein said daughter particles have a smaller band gap energy than that of particles constituting said matrix particles, and possess capability of absorbing ultraviolet light. The composite fine particles are produced by preparing a liquid mixture containing a mixture comprising starting materials for matrix particles and for daughter particles; forming droplets from the liquid mixture; and drying the formed droplets and/or pyrolyzing starting materials for pyrolysis therein. The cosmetics of the present invention contain the above composite fine particles.
摘要:
The present invention is directed to ultraviolet shielding composite fine particles having transparency in a visible light region include (a) matrix particles comprising an aggregate of primary particles having an average particle diameter of from 0.001 to 0.3 .mu.m, the aggregate being formed while the primary particles retain their shapes; and (b) daughter particles having an average particle diameter of from 0.001 to 0.1 .mu.m, the daughter particles being dispersed in and supported by the matrix particles. In the composite fine particles, the daughter particles have a smaller band gap energy than the particles constituting the matrix particles and are capable of absorbing ultraviolet light, and the resulting ultraviolet shielding composite fine particles have substantially no catalytic activity.
摘要:
Ultraviolet shielding composite fine particles having transparency in a visible light region, comprising matrix particles comprising an aggregate of primary particles having an average particle size of from 0.001 to 0.3 .mu.m, the aggregate being formed while the primary particles retain their shapes; and daughter particles having an average particle size of from 0.001 to 0.1 .mu.m, the daughter particles being dispersed in and supported by the matrix particles, wherein the daughter particles have a smaller band gap energy than the particles constituting the matrix particles and are capable of absorbing ultraviolet light, and wherein the surfaces of the composite fine particles are coated with one or more silicones selected from the group consisting of modified silicones, reactive silicones, and silicone-modified copolymers, and wherein the ultraviolet shielding composite fine particles have substantially no catalytic activities. By forming composite fine particles comprising the ultrafine particles having the ultraviolet shielding ability, the composite fine particles of the present invention have substantially no catalytic activities, high transparency in the visible light region, and high shielding ability in the ultraviolet light region.
摘要:
The present invention provides a method for producing ceramic fine particles comprising the steps of supplying gaseous starting materials or starting material droplets to a reaction space arranged in an annular portion between inner and outer cylinders of a coaxial, double-cylinder reaction apparatus, the reaction apparatus having a stationary outer cylinder and a rotatable inner cylinder; and subjecting the gaseous starting materials or the starting material droplets to reaction in the reaction space while rotating the inner cylinder. Also, the present invention provides a production apparatus used therefor. In the present invention, by utilizing the Taylor vortex flow as the flow for a CVD reaction field or a pyrolytic reaction field, uniform ceramic fine particles can be produced at a high yield because of an even temperature distribution, and an even concentration distribution of the reaction gases or an even concentration distribution of the droplet number in the vortex flow, and residence time of the resulting fine particles locked in the vortex flow.