Colored hydrogel objects and their production-containing a water-insoluble opaquing agent
AssigneeIgel International Ltd.
InventorNicholas M. da Costa
Life of this patent
Estimating the term…
Abstract
Shaped organic polymer hydrogels, especially contact lenses, are provided with opaque or translucent coloring so as to be capable of masking effectively any underlying color, e.g. the natural color of the eye. The hydrogel may be rendered opaque by precipitation in situ of a white or yellow water-insoluble, inorganic or organic material e.g. barium sulphate or an optical brightener and then colored with a suitable dyestuff.
Claims10
A shaped organic polymer hydrogel containing within the gel an opaque or translucent, physiologically innocuous, water-insoluble precipitate selected from the group consisting of water-insoluble hydroxides, oxides, sulphates and sulphides of barium, aluminum and zinc in an amount sufficient to render said hydrogel opaque or translucent, and a dye for the hydrogel selected from the group consisting of reactive, solvent, disperse and vat dyes in at least part of those areas containing the said water-insoluble precipitate.
Method of making a shaped organic polymer hydrogel containing within the gel an opaque or translucent, physiologically innocuous, water-insoluble precipitate selected from the group consisting of water-insoluble hydroxides, oxides, sulphate and sulphides of barium, aluminum and zinc in an amount sufficient to render said hydrogel opaque or translucent, and a dye for the hydrogel selected from the group consisting of reactive, solvent, disperse and vat dyes in at least part of those areas containing the said water-insoluble precipitate which comprises applying to a shaped organic polymer hydrogel a solution of a precursor of the water-insoluble precipitate under conditions such that the said solution penetrates substantially into the hydrogel, and then an agent which interacts with said precursor to form said water-insoluble precipitate in situ in the hydrogel, and dyeing with a reactive, solvent, disperse or vat dye at least part of the area in which the precipitate is formed before, during or after the formation of the said precipitate.
Dependencies are inferred from the claim text.