Abstract: The present invention provides a method for the preparation of pigment granules that are readily dispersible, robust, and have a reduced liability to dusting, preferably without the use of substantial quantities of binder, if any at all. The method comprises mixing at least one pigment selected from the group consisting of iron oxides, chromium oxides, cobalt blues, mixed metal oxides, carbon blacks and titanium oxides, with water to form a mixture having a dough-like consistency. The mixture is then extruded through at least one die to form extruded granules, thereby also compacting the mixture, which increases the strength of the granules. The extruded granules are then dried so that the final water content of the granules is less than substantially 5%.
Type:
Grant
Filed:
June 17, 2002
Date of Patent:
May 13, 2003
Assignee:
Elementis UK Limited
Inventors:
Peter Robin Emery, Joseph Hugh McAualay, Peter Dunker
Abstract: The present invention provides a method for the preparation of pigment granules that are readily dispersible, robust, and have a reduced liability to dusting, preferably without the use of substantial quantities of binder, if any at all. The method comprises mixing at least one pigment selected from the group consisting of iron oxides, chromium oxides, cobalt blues, mixed metal oxides, carbon blacks and titanium oxides, with water to form a mixture having a dough-like consistency. The mixture is then extruded through at least one die to form extruded granules, thereby also compacting the mixture, which increases the strength of the granules. The extruded granules are then dried so that the final water content of the granules is less than substantially 5%.
Type:
Application
Filed:
June 17, 2002
Publication date:
April 10, 2003
Applicant:
Elementis UK Limited
Inventors:
Peter Robin Emery, Joseph Hugh McAualay, Peter Duncker
Abstract: A process for preparing zinc oxide comprises introducing, into an atmosphere, an aqueous solution of a zinc salt that is thermally decomposable to zinc oxide, the atmosphere having a temperature sufficient to decompose the salt to the oxide, and recovering zinc oxide. The zinc oxide so-prepared is in the form of discrete particles which can have an average particle size of 0.08 .mu.m or less in diameter and a surface area of at least 12.5 m.sup.2 /g and which is also free of zinc metal. The small particle size zinc oxide is particularly useful as a UV absorbing/scattering additive.