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. 10, 1992
Filed:
Aug. 31, 1990
Heinrich Follmann, Minden, DE;
Dietrich Hoffmann, Roedersheim-Gronau, DE;
Wolfgang Sliwka, Weinheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Spherical, hard mono- or oligodisperse particles of diameter from 0.1 to 100 .mu.m are prepared by condensation of partially etherified melamine-formaldehyde precondensates which form a clear solution in water in every ratio, in an aqueous solution of a water-soluble polymer which has strongly acid groups and a K value of from 100 to 160, at pH 3 to 6 and at 20.degree. to 100.degree. C., and condensation of the resulting cloudy solution is continued until the precondensate has been consumed, resulting in a dispersion of the particles. The dispersion is neutralized. The particles can be used in the form of the aqueous dispersion or after isolation from the dispersion. The particles are spherical, hard and non-swellable and can be used, for example, as sizes for plastics, polishes, delustrants, extruders and/or as pigment. The process makes it possible to produce particles of predetermined size and size distribution.