Ferrania, S.p.a.

Ferraria Technologies S.p.a.

Mauro Avidano

Simone Angiolini

Giuseppe Rocca

Paolo Salvarani

Roberto Bracco

Raffaella Biavasco

Luisa Tavella

Diego Brignone

Mario Mariotti

Stefania Ghirardo

Alessandro Gunnella

Ezio Astengo

The present invention refers to a polymeric optical film the polymer of the polymeric optical film consisting essentially of one or more polyarylates having repeating units represented by the general structure:wherein A represents one or more different bisphenolfluorene radicals having the general formula (I):wherein Rand Rindependently represent an alkyl group, a halogen atom, an alkoxy group, an acyl group, a phenyl group or a nitrile group, with the proviso that Rand Rare not both an alkyl group; R, R, Rand Rrepresent a hydrogen atom, an alkyl group, a halogen, an alkoxy group, an acyl group, a phenyl group, a nitro group, or a nitrile group, with the proviso that when Rand Rare both bromide atoms, at least one of R, R, Rand Ris different from hydrogen atom;B represents one or more different dicarboxy radicals having the formula:wherein X is a divalent aromatic hydrocarbon group having from 6 to 20 carbon atoms, and n is the number of the repeating units which build up the polymer and is a positive integer higher than 20. The optical film of the present invention has excellent mechanical and thermal properties, a high Tg and does not readily yellow upon exposure to light.

Optical film comprising polyarylates containing bis-(hydroxyphenyl)-fluorene-ortho-disubstituted bisphenols

A 9,9-bis (4-hydroxyphenyl) fluorene compound showing a melting curve maximum of at least 226.00&deg; C. and a melting curve width at 5% equal to or lower than 1.30&deg; C. A purification process for the preparation of 9,9-bis (4-hydroxyphenyl) fluorene compounds comprising a first purification step employing acetonitrile and a second purification step employing a solvent selected from the group consisting of aliphatic alcools, a mixture of aromatic hydrocarbons and aliphatic alco-hols and a mixture of aromatic hydrocarbons and nitrites. A synthesis method for the preparation of 9,9-bis (4-hydroxyphenyl) fluorene compounds comprising the steps of (a) reacting in an organic solvent a phenol compound with a 9-fluorenone in the presence of an acidic condensing agent, (b) separating the crude 9,9-bis (4-hydroxyphenyl) fluorene, and (c) purifying the crude 9,9-bis (4-hydroxyphenyl) fluorene, wherein the purifying method comprises a first purification step employing acetonitrile solvent and a second purification step employing a solvent selected from the group consisting of aliphatic alcools, a mixture of aromatic hydrocarbons and aliphatic alcohols and a mixture of aromatic hydrocarbons and nitrites.

High purity 9,9-bis-(hydroxyphenyl)-fluorene and method for the preparation and purification thereof

The present invention relates to a light-sensitive emulsion, and a light-sensitive photographic material containing the same, comprising silver bromoiodide grains of a core shell structure comprising a) an inner core consisting essentially of silver bromide or silver bromoiodide, the silver iodide content of said inner core being within the range of 0 to 10 mole %, and b) a plurality of shells consisting essentially of silver bromide or silver bromoiodide, wherein a pure silver iodide phase representing from 0.1 to 5 mole % of the total silver halide grain content is interposed between two adjacent shells, and wherein at least one of said adjacent shells has a silver iodide content higher than 5 mole %.

Silver bromoiodide core-shell grain emulsion

Silver halide color photographic light-sensitive elements having improved image quality

Growing community of inventors

Asti, Italy

Mauro Avidano