Patent · US Expired

Nanoparticulate, redispersible zinc oxide gels

US6710091B1 · kind B1 · utility

26Cited by

4References

6Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Hermann-Jens Womelsdorf · Leverkusen, DE
Werner Hoheisel
Gerd Passing · Wermelskirchen, DE

Key dates

Filing date	Aug 21, 2001
Grant date	Mar 23, 2004
Priority date	—
Expiry date	Aug 21, 2021

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08K2003/2296
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A method for the preparation of nano size zinc oxide particles having an average primary particle diameter of less than or equal to 15 nm, which are redispersible in organic solvents and/or water, by basic hydrolysis of at least one zinc compound in alcohol or an alcohol/water mixture. The hydrolysis is carried out with substoichiometric amounts of base, based on the zinc compound. The precipitate which originally forms during hydrolysis is left to mature until the zinc oxide has completely flocculated. This precipitate is then thickened to give a gel and separated off from the supernatant phase.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.