David B. Knowles

Bio: David B. Knowles is an academic researcher. The author has contributed to research in topics: Pyran & Substituent. The author has an hindex of 1, co-authored 1 publications receiving 239 citations.

Photochromic naphthopyran compounds

Abstract: Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds substituted at the 3 position of the pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl substituent. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

High-intensity, persistent photoluminescent formulations and objects, and methods for creating the same

Abstract: Disclosed are photoluminescent formulations, comprising an effective amount of photoluminescent phosphorescent materials, which exhibit high luminous intensity and persistence. Also disclosed are photoluminescent objects formed by applying at least one photoluminescent layer, formed from photoluminescent formulations, to preformed articles. Further disclosed are methods for creating photoluminescent objects.

Photoluminescent Compositions, Methods of Manufacture and Novel Uses

Abstract: A novel marking system is provided. The marking includes photoluminescent materials and provides for shifting of excitation energy. The marking provides flexibility for identification and tracking, both in stealth and non-stealth appearances.

Photochromic indeno-fused naphthopyrans

Abstract: Described are novel photochromic indeno-fused naphthopyran compounds, examples of which are naphthopyran compounds having a substituted or unsubstituted indeno group, the 2,1 positions of which are fused to the f side of the naphtho portion of the naphthopyran, and certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 6, 7, 8, 9, 10, 11, 12, or 13 carbon atoms of the compounds. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds, are also described.

Polyurethanes, articles and coatings prepared therefrom and methods of making the same

Abstract: The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

Photochromic substituted naphthopyran compounds

Abstract: Described are novel reversible photochromic naphthopyran compounds, examples of which are 3H-naphtho[2,1-b]pyrans having an acyl or aroyl oxy-bearing substituent at the number 6 carbon atom and certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 7, 8, 9 or 10 carbon atom of the naphthopyran. These compounds may be represented by graphic formula (I). Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline) type compounds, are also described.