Abstract: A multi stage process for the production of polycarbonates having low monomer content is disclosed. The process entails, in sequence, (i) transesterifying in the melt at least one dihydroxyaryl compound with at least one diaryl carbonate in the presence of at least one onium catalyst to produce a polycondensate that contains monomers, (ii) introducing into the polycondensate an inhibitor in an hypostoichiometric amount in relation to the catalyst and (iii) reducing in a finishing reactor the content of monomers in said polycondensate. The polycarbonate thus produced is characterized in that it contains less than 350 ppm of diphenyl carbonate, less than 40 ppm of 2,2-bis-(4-hydroxyphenyl)propane and less than 150 ppm of phenol.

Abstract: An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.

Abstract: The invention relates to a novel polymethine dyes containing at least one acylsulfonamido group of the formula (I) in which n, Y, A and R have the meaning given in the claims, and at least one compound of the formulae (a) to (n) given in the claims. The polymethine dyes according to the invention are suitable for use as dyes and/or labels, in particular for staining or labeling biomolecules.

Abstract: An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.

Abstract: A multi stage process for the production of polycarbonates having low monomer content is disclosed. The process entails, in sequence, (i) transesterifying in the melt at least one dihydroxyaryl compound with at least one diaryl carbonate in the presence of at least one onium catalyst to produce a polycondensate that contains monomers, (ii) introducing into the polycondensate an inhibitor in an hypostoichiometric amount in relation to the catalyst and (iii) reducing in a finishing reactor the content of monomers in said polycondensate. The polycarbonate thus produced is characterized in that it contains less than 350 ppm of diphenyl carbonate, less than 40 ppm of 2,2-bis-(4-hydroxyphenyl)propane and less than 150 ppm of phenol.

Abstract: A polymer of the formula (I): in which X1 means H or (R1)1+1—L1CO—, X2 means —(L2)m—OH or R1 means —COO−M+, —SO3−M+ or (M+)2PO32−, L1 means alkylene, arylene, aralkylene or cycloalkylene, L2 means the residue of a polyether having an average molecular weight of 200 to 3000 (number average), M+ means a cation, l means a number from 0 to 4, m means a number 0 or 1 and n means a number from 0 to 20, wherein m+n is ≧1.

Abstract: A color photographic film having a support, 2 or 3 red-sensitive, cyan-coupling silver halide emulsion layers, 2 or 3 green-sensitive, magenta-coupling silver halide emulsion layers, 2 or 3 blue-sensitive, yellow-coupling silver halide emulsion layers, conventional interlayers and protective layers together with a yellow filter layer arranged closer to the support than the blue-sensitive layers, wherein at least one green-sensitive silver halide emulsion layer is arranged further away from the support than all the other photosensitive layers, exhibits improved sharpness without color distortion if at least 50% of the projected surface area of the silver halide emulsion of the green-sensitive silver halide emulsion layer, of which there is at least one, consists of tabular silver halide grains having an aspect ratio of at least 3.

Abstract: A colour photographic material in which a package of layers is provided which consists, in the stated sequence, of (a) a silver halide-free layer containing colour coupler, (b) a layer containing silver halide and (c) a silver halide-free layer containing colour coupler, wherein at least one of layers (a) and (c) consists to an extent of at least 20 vol. % of a synthetic polymer, is distinguished by an improved grain/sensitivity ratio.

Abstract: A color photographic silver halide material having a support, at least one photosensitive silver halide emulsion layer and a polymeric cyan coupler associated with the photosensitive silver halide emulsion layer, which coupler contains polymerised units of the formula (I) ##STR1## in which X means a hydrogen atom or a group eliminable under chromogenic development conditions,R.sub.1 means a hydrogen or halogen atom, an optionally substituted alkyl, aryl or acylamino group,R.sub.2 means an optionally substituted alkyl, aryl or heterocyclic group andn means a number from 0 to 3, is distinguished by improved stability of the cyan dye.

Abstract: A color photographic silver halide material having at least two blue-sensitive, yellow coupler containing silver halide emulsion layers, at least two green-sensitive, magenta coupler containing silver halide emulsion layers and at least two red-sensitive, cyan coupler containing silver halide emulsion layers together with conventional interlayers and protective layers, wherein photosensitive layers of identical color sensitivity differ with regard to the photographic sensitivity thereof and the more highly sensitive layers are arranged further away from the support than the less sensitive layers of identical color sensitivity, which material contains, in a layer which is arranged further from the support than the most highly sensitive, blue-sensitive layer, both at least one yellow coupler and at least one magenta or cyan coupler, is distinguished by improved grain and sensitivity combined with very good color reproduction.