Photoreactive lenses with adamantane spiro compounds
AssigneePlessey Incorporated
InventorsHarry G. Heller, Stephen N. Oliver, John Whittall, Jack Brettle, Clive Trundle, Martin W. Baskerville
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AssigneePlessey Incorporated
InventorsHarry G. Heller, Stephen N. Oliver, John Whittall, Jack Brettle, Clive Trundle, Martin W. Baskerville
Estimating the term…
Photoreactive plastics lenses are disclosed which are coated or impregnated with an adamantane 2-spiro-benzo or naphthopyran and with a blue coloring photochromic benzo- or naphthopyran having a nitrogen containing substituent in the 2-position in the pyran ring. The lenses darken in sunlight and fade rapidly at ambient temperatures in the dark or in white light which does not contain a U.V. component. The combination of the yellow/orange coloring adamantane 2-spiro pyran compound with the purple/blue coloring pyran gives a desired brown/grey coloration in the sunlight-darkened lens. The invention includes novel blue-coloring pyran compounds in which the nitrogen-containing substituent in the 2-position is a phenyl group having an amino or substituted amino or nitrogen-containing heterocyclic substituent in the ortho- or para-position of the phenyl group. The basic chromene structure and the suffix N will be used to distinguish the blue-coloring pyran compounds having a nitrogen-containing substituent, namely: ##STR1##
An opthalmic or plano-lens which darkens in sunlight and reverts to a pale or colourless condition in white light at normal ambient temperatures, wherein the lens has incorporated therein or coated thereon at least two heliochromic compounds, one of said compounds comprising an adamantane spiro-benzopyran or spironaphthopyran in which an adamantane group is present in the 2-spiro-position of the benzopyran or naphthopyran ring and a second compound comprising a benzo or naphthopyran having a nitrogen-containing substituent in the 2-position of the pyran ring.
Dependencies are inferred from the claim text.