The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 22, 1994
Filed:
Sep. 30, 1992
Carole A Tapley, Stockton on Tees, GB;
Tioxide Specialties Limited, London, GB;
Abstract
An oil dispersion which is substantially transparent to visible light comprises an oil, particles of zinc oxide having an average size of from 0.005 to 0.15 micron and an organic dispersing agent. The solids content of the dispersion is at least 30 weight percent, its extinction coefficients at 308 nm (E(308)) and 360 nm (E(360)) wavelengths are both at least 9 liters per gram per centimeter and the ratio E(360):E(308) is in the range 0.75:1 to 1.5:1. A method of preparing the dispersion is also described in which the ingredients are milled together in the presence of a particulate grinding medium until the required particle size and optical properties are obtained. The dispersions are useful in sun-screening preparations and especially those products designed to provide a balanced protection from UVA and UVB radiation.