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US 4,661,164 AGranted
Method of tinting a mineral filler
AssigneeFranklin Industries, Inc.
InventorNelson Severinghaus, Jr.
Life of this patent
Estimating the term…
Abstract
A method of increasing the whiteness of a mineral filler, such as limestone, having a natural yellow tint, including the grinding of the limestone to a pulverulent size and introducing into the limestone, preferably while it is being ground, a blue pigment in an amount sufficient to optically transform the natural yellow tint to a predetermined degree of whiteness.
Claims13
A method of increasing the whiteness of a mineral filler having a natural tint, comprising the steps of:
- (a) introducing into a predetermined amount of the mineral filler a pigment of a color and in an optimum amount sufficient to optically transform the natural tint to a predetermined degree of whiteness in said mineral filler,
- (b) intimately intermixing with said predetermined amount of mineral filler said optimum amount of pigment in such a manner that said pigment is widely dispersed in said mineral filler and optically transforms said natural tint to said predetermined degree of whiteness in said mineral filler.
Dependencies are inferred from the claim text.