Abstract: An optical media comprising a polymeric material film, characterized in that said polymeric material is a polyester obtained from a 9,9-bis(4-hydroxyphenyl)fluorene derivative and a mixture of terephthalic acid and isophthalic acid derivatives, said polymeric material having a glass transition temperature higher than 315° C. and a yellowing coefficient Yc lower than 0.0060.

Abstract: An optical media comprising a polymeric material film, wherein said polymeric material is a polyester obtained from a 9,9-bis(4-hydroxyphenyl)fluorene derivative and a mixture of terephthalic acid and isophthalic acid derivatives, said polymeric material having an inherent viscosity lower than 0.80 dl/g and a yellowing coefficient Yc lower than 0.0050.

Abstract: 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 R1 and R2 independently represent an alkyl group, a halogen atom, an alkoxy group, an acyl group, a phenyl group or a nitrile group, with the proviso that R1 and R2 are not both an alkyl group; R3, R4, R5 and R6 represent 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 R1 and R2 are both bromide atoms, at least one of R3, R4, R5 and R6 is 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

Abstract: 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: 1

Abstract: The present invention refers to an optical film comprising one or more polyarylates having at least some units represented by the general structure: wherein A represents one or more different bisphenolfluorene radicals having the general formula (I):  wherein R1 and R2 independently represent an alkyl group, a halogen, an alkoxy group, an acyl group, a phenyl group or a nitrile group, with the proviso that R1 and R2 are not both an alkyl group; R3, R4, R5 and R6 represent a hydrogen atom, an alkyl group, a halogen, an alkoxy group, an acyl group, a phenyl group, a nitro group, or a nitrile group; B represents one or more different dicarboxy radicals having the formula:  wherein X is a divalent hydrocarbon group having from 1 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.

Abstract: A 9,9-bis (4-hydroxyphenyl) fluorene compound showing a melting curve maximum of at least 226.00° C. and a melting curve width at 5% equal to or lower than 1.30° 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.

Abstract: A 9,9-bis (4-hydroxyphenyl) fluorene compound showing a melting curve maximum of at least 226.00° C. and a melting curve width at 5% equal to or lower than 1.30° 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.

Abstract: The present invention refers to an optical film comprising one or more polyarylates having at least some units represented by the general structure: 1

Abstract: 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 %.

Abstract: The present invention relates to a light-sensitive silver halide color multilayer photographic material which comprises a support base having coated thereon at least three red-sensitive emulsion layers having different sensitivity, at least three green-sensitive emulsion layers having different sensitivity, and at least two yellow-sensitive emulsion layers having different sensitivity, wherein (a) a core-shell silver halide emulsion having an average silver iodide content lower than 10% mol is present in at least one of the lowest sensitive red-, green- and yellow layers, (b) a yellow dye forming malonodiamide DIR coupler having in the coupling position thereof a 4,7-dihalogen-2-benzotriazolyl group is present in both the medium sensitive red- and green-sensitive layers, and (c) a yellow dye forming DIR coupler having a 1,2,4-triazolyl group attached to the coupling position, such 1,2,4-triazolyl group comprising a hydrolizable alkoxy- or aryloxy-carbonyl group attached to a benzytlthio substituent on the