Abstract: Optical data carriers whose information layer comprises at least one light-absorbent compound which is a Co(III) phthalocyanine in which the Co metal centre bears an axial substituent R1 and an axial coordinated ligand R2, where R1 is CN, SCN, halogen, in particular Cl, Br or F, alkoxy, aryloxy, arylthio or alkylthio and R2 is no ligand or substituted or unsubstituted amine, water, an alcohol, H2S, a thioalcohol or an isonitrile.

Abstract: An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40° C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40° C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.

Abstract: A polycarbonate resin that after alkaline hydrolysis with sodium hydroxide contain an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen, C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, said amount measured after alkaline hydrolysis with sodium hydroxide by high pressure liquid chromatography.

Abstract: A substrate material, preferably polycarbonate, suitable for producing transparent injection-molded coated disks is disclosed. The material is characterized in that a substrate molded therefrom has an electrical field (measured within 5 minutes of its molding and at a distance of 100 mm from the surface) of ?30 to 0 kV/m.

Abstract: A polymeric material suitable for making a substrate for optical data storage disks is disclosed. The material, preferably aromatic polycarbonate is characterized in that the potential on 95 to 100% of the total surface of a disk molded therefrom is from ?1.5 to +1.5 kV, and in that the potential on 0 to 5% of the total surface of said disk is between ?1.5 and ?2.5, and +1.5 to +2.5, and in that the potential on no more than 1% of the total surface of said disk is less than ?2.5 kV and more than +2.5 kV. The potential measurements are carried out by means of a Monroe probe at a distance of 3.5 mm from the surface of the disk, the scanning region is in each case 12 cm in the X- and Y-direction, and in each case in steps of 2 mm in the X- and in the Y-directions.

Abstract: Polycarbonate resin containing small amounts of carbamate compounds is disclosed. The resin that contains at least one of compounds conforming to wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, R3 and R4 independently of one another represent hydrogen, C1-C12-alkyl, or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and R5 denotes hydrogen, C1-C12-alkyl, C5-C12-cycloalkyl, phenyl or cumyl, are characterized by their low electrostatic field and therefore suitable for making optical storage media.

Abstract: Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound.

Abstract: An optical fiber that contains a core of polycarbonate and a coating is disclosed. The coating is a polymer that contains structural units conforming to specified formulae. Also disclosed is a process for producing the inventive fibers and their use for transmitting optical signals.

Abstract: Optical fibers suitable for transmission of optical signals and comprising a core that contains polycarbonate are disclosed. The polycarbonate is characterized in its low content of insoluble particles.

Abstract: An optical recording medium having at least a recording layer 11 and a light transmitting layer 13 formed on a substrate 10, in which the recording layer 11 is made of an organic material for absorbing an incident light of wavelength of 360 nm to 460 nm, and inducing physical change or chemical change to vary the refractive index, the light transmitting layer 13 is 10 ?m to 177 ?m in thickness, the relation between absorption coefficient “k” and pyrolysis temperature Tdec of organic material is 950(° C.)<(Tdec (° C.)?20)/k<4100° C.??(1), and the absorption coefficient “k” is k>0.0.

Abstract: Novel squarylium compounds for optical data carriers have been found. The latter comprise a preferably transparent substrate to whose surface a light-writable information layer, if desired one or more reflection layers and a further substrate or a protective layer have been applied and can be written on and read by means of red light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder. They are characterized in that at least the said squarylium compounds are used as light-absorbent compound.

Abstract: An optical fiber that contains a core of polycarbonate and a coating is disclosed. The coating is a polymer that contains structural units conforming to specified formulae. Also disclosed is a method for preparing the inventive fibers and the use thereof for transmitting signals.

Abstract: A thermoplastic molding composition especially suitable for preparing optical data carriers is disclosed. The composition contains polycarbonate resin, at least one mold release agent and at least one phosphite having a defined structural formula. The optical data carriers include compact discs, video discs, digital versatile discs and further optical data carriers which may be written and erased one or more times.

Abstract: The invention relates to an optical data carrier having a preferably transparent substrate that has optionally previously been coated with one or more reflection layers and to the surface of which has been applied a light-writeable information layer, optionally one or more reflection layers, and optionally a protective layer or a further substrate or a covering layer, such that the optical data carrier can be written on or read by means of blue light (preferably laser light having a specified wavelength) or by means of infrared light (preferably laser light having a specified wavelength), wherein the information layer contains (i) light-absorbent phthalocyanine dyes of the formula (I) where Me is a doubly axially substituted Si, Ge, and Sn atom, Pc is an unsubstituted phthalocyanine, and X1 and X2 are each independently halogen, and (ii) optionally, a binder.

Abstract: Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound.

Abstract: A process for the preparation of optical data carriers made of a particualr polycarbonate is disclosed. The polycarbonate is prepared by the phase boundary process that entails reacting at least one dihydroxydiarylalkane in the form of its alkali metal salts with phosgene in the heterogeneous phase in the presence of sodium hydroxide solution and an organic solvent. The process is characterized in that the feedstock have but low content of Fe, Cr, Ni, Zn, Ca, Mg, Al metals or homologues thereof, and in that the organic solvent is separated off, and in that the polycarbonate which is obtained is worked up. The resulting polycarbonate is particularly useful in producing optical data carriers.

Abstract: Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound.

Abstract: Optical data medium containing in the information layer, a dye as a light-absorbing compound Abstract optical data medium containing a preferably transparent substrate which is optionally already coated with one or more barrier layers and on the surface of which an information layer which can be recorded on using light, optionally one or more barrier layers, and a cover layer containing a radiation-cured resin, have been applied, which data medium can he recorded on and read using focused blue light through the cover layer on the information layer, preferably laser light with the wavelength between 360 nm and 460 nm, the information layer containing a light-absorbing characterized in that at least one dye is used as the light-absorbing compound wherein the cover layer dies have a total thickness of 10 &mgr;m 177 m and the numerical aperture NA of the focusing objective lens setup is greater or equal 0.8.

Abstract: A polycarbonate molding having improved optical properties is disclosed. The molding features an angle of deflection &agr;&egr; (min) determined in a accordance with DIN 52305-A-AS of ≦2.0 and a refractive index D&egr; (min) determined in accordance with DIN 52305-A-AZ of ≦0.05. The molding is prepared from a molding composition that contains a branched polycarbonate having a weight average molecular weight of 25,000 to 40,000 and melt volume rate of 2 to 20 cm3/10 min (300° C.; 1.2 kg) determined in accordance with ISO 1133.

Abstract: A thermoplastic polymer mixture comprising at least on thermoplastic polycarbonate polymer, and at least one mold release agent including at least one polyol component, is described. At least one polyol component (I) of the mold release agent consists of a parent substance with at least 4 carbon atoms, at least 3 hydroxyl groups, at least one hydroxyl group esterified with an aliphatic carboxylic acid, and at least one free hydroxyl group.