Patent Picks are chosen by the editors from publicly available sources. Today's feature discloses a novel polymeric thickener free from acrylamide fragments—and therefore, free from odor.
Polymeric thickening agent preparation and use
U.S. Patent 9144610
Publication date: Sept. 29, 2015
Disclosed in this patent is a composition including an oil phase, an aqueous phase and at least one water-in-oil (w/o) emulsifying system in the form of a positive latex. The composition includes a straight, branched or cross-linked anionic polyelectrolyte, including: a) a non-zero molar proportion of monomer units from acrylic acid in free or partially salified form; and b) a non-zero molar proportion of monomer units from the acid of the formula:
where n is a number greater than or equal to one (1) and less than or equal to five (5), and in free or partially salified form. A method for preparing the composition, a polymer powder and its use as a thickening agent for cosmetics or pharmaceuticals also are described.
According to the inventors, self-invertible inverse latexes exist in the prior art. However, their thickening power is not entirely satisfactory and their unpleasant odor due to the presence of a nitrogen base limits their use in the cosmetics industry. For example, one European patent application discloses copolymers of acrylic acid with acrylic acid dimer, which are used as photographic film layers. A German patent application also describes copolymers of 2-acrylamido-1-methylpropanesulfonic acid and carboxyethylacrylate, which are used in the cosmetics industry. The present invention is said to provide better thickening without unpleasant odor.