Delaminated transparent talc
AssigneeAmerican Westmin, Inc.
InventorsMary Ann Nordhauser, James Robert Anderson
Life of this patent
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Abstract
A delaminated talc has a plurality of high aspect ratio, smooth surface particles. The aspect ratio of the particles is determined by dividing their extent along an upper surface thereof by their thickness. The upper surface is substantially parallel to the lamellar interface direction and the thickness is measured perpendicularly to the interface direction. The upper, lower and side surfaces of the particles are smooth, lacking acute angularity and staircase effect which give rise to increased coefficient of friction and light scattering. The talc is especially suitable in cosmetic and pharmacologic preparations due to its high degree of transparency, skin adhesiveness, lubricity and spreadability.
Claims10
A delaminated talc, comprising talc particles at least 10% of which have an aspect ratio of 5 or greater, the aspect ratio of each of said particles determined by dividing said particle's extent along an upper surface thereof by said particle's thickness, said upper surface being substantially parallel to a lamellar interface direction and said thickness being measured perpendicularly to said lamellar interface direction, said at least 10% of said talc particles having substantially parallel, smooth top and bottom surfaces with comparably sized respective surface areas and an outer peripheral surface defining a profile of said particles which can be approximated by a set of connected curves having a radii of curvature greater than 0.125 D.sub.S.
Dependencies are inferred from the claim text.