Abstract: The invention relates to the use of branched aliphatic hydrocarbons such as squalane in compositions based on thermoplastic polymer, in particular on polycarbonate, which are used for producing molded parts used in LED lighting units, such as covers for instance. According to the invention it has been found that the use of branched aliphatic hydrocarbons makes it possible to enhance the total transmission and the transmission in the range from 360 to 460 nm, thus making corresponding compositions particularly suitable for producing molded parts for use in combination with white LED light sources. It has additionally been shown that yellowing and haze are simultaneously reduced.

Abstract: The invention relates to the use of branched aliphatic hydrocarbons such as squalane in compositions based on thermoplastic polymer, in particular on polycarbonate, which are used for producing molded parts used in LED lighting units, such as covers for instance. According to the invention it has been found that the use of branched aliphatic hydrocarbons makes it possible to enhance the total transmission and the transmission in the range from 360 to 460 nm, thus making corresponding compositions particularly suitable for producing molded parts for use in combination with white LED light sources. It has additionally been shown that yellowing and haze are simultaneously reduced.

Abstract: The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcycloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

Abstract: The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcycloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

Abstract: The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcyloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

Abstract: The invention relates to an efficient continuous method for producing polycarbonates according to the phase interface method.

Abstract: The invention relates to an efficient continuous method for producing polycarbonates according to the phase interface method.

Abstract: The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcyloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

Abstract: The present invention relates to a method for automatically determining the relative solution viscosity and/or the melt volume flow rate of a polymer, during a phase of the process for producing the polymer, where the polymer is in a solution with 10 to 20% by weight of the polymer in an organic solvent. The method includes continuously removing a substream of the polymer solution from a component of the process for producing the polymer, wherein the polymer solution is essentially free from inorganic salts; removing a sample having a volume of from 1 to 10 ?l from the substream; introducing the sample into a gel permeation chromatography apparatus and determining the gel permeation chromatography data for the polymer; and automatically determining the relative solution viscosity and/or the melt volume flow rate of the polymer from the data obtained from the gel permeation chromatogram, on the basis of calibration relationships.

Abstract: Linear polycarbonate resin virtually free of surface defects that impair the suitability of the resin for demanding optical application is disclosed. Also disclosed is a process for the manufacture of the resin. The surface defects included in the resin are in the form of transparent fluorescing particles, the particle count of which portion that are 15 and 250 ?m in size, is up to 1.8 counts/g, said count being determined by exciting the residue remaining after filtering a solution of said polycarbonate in methylene chloride through a Teflon filter of 5 ?m pore size at a wavelength of 400-440 nm, 25× overall magnification and illumination time of 40 millisec. The polycarbonate is suitable for making films of improved optical properties.

Abstract: Linear polycarbonate resin virtually free of surface defects that impair the suitability of the resin for demanding optical application is disclosed. Also disclosed is a process for the manufacture of the resin. The surface defects included in the resin are in the form of transparent fluorescing particles, the particle count of which portion that are 15 and 250 ?m in size, is up to 1.8 counts/g, said count being determined by exciting the residue remaining after filtering a solution of said polycarbonate in methylene chloride through a Teflon filter of 5 ?m pore size at a wavelength of 400-440 nm, 25× overall magnification and illumination time of 40 millisec. The polycarbonate is suitable for making films of improved optical properties.

Abstract: Polycarbonate substrates having low concentration of defects are disclosed. The substrates are suitable for producing molded articles characterized by low cloudiness.

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: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

Abstract: A process for the preparation of polycarbonate by the phase boundary process is disclosed. The process 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 transparent shaped articles.

Abstract: Polycarbonate substrates having low concentration of defects are disclosed. The substrates are suitable for producing molded articles characterized by low cloudiness.

Abstract: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

Abstract: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

Abstract: A branched polycarbonate resin suitable for making containers is disclosed. The polycarbonate is characterized in that at 260° C. and shear rate of 10 s−1 it has a melt viscosity of 5500 to 900 Pas, and in that at 260° C. and shear rate of 1000 s−1 it has a melt viscosity of 880 tom 1500 Pas, and in that it has a melt flow index (MFR) of 0.1 to 3.0 g/10 min. A container made of the polycarbonate exhibits great breaking strength.