Fine zinc oxide particles, process for producing the same, and use thereof

Zinc oxide-polymer composite particles which comprise zinc oxide fine particles and a polymer, the proportion of said zinc oxide fine particles being 50 to 99% by weight based on the total weight of said zinc oxide fine particles and said polymer, and the composite particles having an outer shell composed of a mixture and/or a composite of said zinc oxide fine particles and said polymer with the inside of said outer shell being hollow.

Composite particles comprising:

• (i) zinc oxide-based particles comprising a metal oxide co-precipitate containing, as a metallic component, (a) at least one element additive selected from the group consisting of metals of Group IIIB and metals of Group IVB, and (b) zinc, and having a zinc content of 80 to 99.9% in terms of the ratio of the number of zinc atoms to the total number of the atoms of said metallic components, and having X-ray crystallographically exhibiting zinc oxide crystalline properties, and (ii) a polymer.

Inorganic compound particles containing 60 to 100% by weight of zinc oxide and having on their surface a cluster of thin plate zinc oxide crystals with their tips projecting outward.

A process for producing zinc oxide fine particles comprising:

• forming a mixture comprising a zinc source, a carboxyl-containing compound, and an alcohol, and
• heating said mixture to form said particles.

A process for producing zinc oxide-based particles comprising:

• forming a mixture comprising a zinc source, a carboxyl-containing compound, at least one element additive selected from the group consisting of the group IIIB metal elements and the group IVB metal elements, and an alcohol, and
• heating said mixture at a temperature of 100° C. or above to form said particles.

A process for producing inorganic compound particles having on their surface a cluster of zinc oxide crystals with their tip projecting outward, which comprises:

• forming a mixture comprising a zinc source, a carboxyl-containing compound, lactic acid or a compound thereof, and an alcohol, and
• heating said mixture at a temperature of 100° C. or above to form said particles.

A process for producing zinc oxide-polymer composite particles, which comprises:

• forming a mixture comprising a zinc source, a carboxyl-containing compound, a polymer, and an alcohol at a temperature of 1000 or above;
• and
• heating said mixture to form said particles.