Light filters using yellow melanin and melanin-like oligomers and photochromic dyes
AssigneePhotoprotective Technologies Incorporated
InventorsJames M. Gallas, Ira Hessel
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Abstract
Selective fractionation and separation of melanin and use of fractionated or separated melanin in connection with light filters is disclosed. Further, light filters that use yellow melanin or melanin like materials prepared to have a yellow color and a melanin transmission spectrum in combination with a photochromic dye are disclosed. The yellow form of melanin has minimal impact on the perception of light intensity with transmission values greater than 80%. The combination allows for a single light filter suitable for both night driving and sunglass applications and which also preserve color perception.
Claims7
A method of preparing a light filter for providing protection from radiation, comprising the steps of:
- subjecting a mixture containing melanin to chromatography;
- separating at least one melanin fraction from the mixture by size exclusion to obtain a first melanin fraction;
- separating a second melanin fraction from the mixture to obtain a second melanin fraction;
- and combining melanin from the first melanin fraction with a transparent substrate to form the light filter having a haze level of less than 1%.
Dependencies are inferred from the claim text.