Bayer Aktiengesellschaft

Bayer Materialscience Ag

Udo Wolf

Burkhard Kohler

Dieter Br&uuml;ck

Herbert Eichenauer

Wolfgang Ebert

Wilfried Haese

Eckhard Wenz

Manfred Schreckenberg

Hans-Georg Pirkl

Klaus Kraft

Bahman Sarabi

Wolfgang Russeler

Vera Buchholz

Jeffrey Bolton

Heinz-Dieter Brandt

Heinz-Herbert Müller

Jochen Mahrenholtz

Wilfried Cramer

Alfred Zembrod

Heinz-Josef Hamacher

Martin Schiffhauer

Marcus Brand

Martin Gerlach

Lutz Spauschus

Claus Riehle

Johannes Schweer

Hans Dohmen

Jurgen Diefendahl

Helmut Gorner

Frank Hilgers

Eckhard Wendt

Klaus Jäger

Rainer Giesen

Ralf-Jürgen Born

Wilhelm Bergmeier

Christof Boden

Andrea Wimschneider

Stefan Dresely

The invention relates to a method for determining the isomer composition in an isocyanate isomer mixture, wherein a spectrum of the isomer mixture is recorded and the spectrum is entered into a chemometric calibration model.

Method and device for determining the isomer composition in isocyanate production processes

A process for monitoring and/or controlling a nitrating process, having the following steps:

Process for monitoring and controlling nitrating processes with the aid of an online spectrometer

A method of using Raman Spectra for determining the progress of a graft polymerization reaction is disclosed. The method entails (a) measuring at the beginning of the reaction and at a plurality of time intervals in the course of the reaction, continuously and on-site, the Raman spectrum in the wave number range of 100 to 4000 cmof one or more of the monomers and/or polymers entailed in the reaction and of at least one internal standard and (b) recording the spectra and (c) adding reaction partners necessary to the reaction continuously and/or discontinuously and (d) calculating the change in concentration of the monomers and polymers by comparing the spectra of the monomers or polymers with the internal standard.

Determining the reaction progress of graft polymerization reactions

A pressure-resistant process window ( ) for visual or spectroscopic examinations of pressurized products in pipes and reactors. The process window ( ) consists of at least a measurement-cell body ( ), which is connected to the pipe or the reactor, and a transparent window pane ( ), a seal ( ) between the measurement-cell body ( ) and the window pane ( ) for sealing the reactor or pipe interior off from the environment, where the window pane ( ) is held against the measurement-cell body ( ) in a sealing manner by use of a screw barrel ( ) having an external thread ( ), which can be screwed into a hollow barrel ( ) with internal thread ( ) which is connected to the measurement-cell body ( ).

Pressure-proof process window

This invention relates to a procedure for the controlled production or for the modification of polymeric products using IR-ATR spectroscopy, wherein the case of a polymerization reaction the extinction is determined of the characteristic IR absorption bands for the monomer used and the resulting polymeric product or in the case of a polymer modification the characteristic IR absorption bands of the starting material used and of the modified polymeric product are determined, the degree of conversion or the degree of modification is calculated from the absorption bands, and when the desired degree of conversion or the desired degree of modification is reached the reaction is stopped by suitable measures. By means of the procedure, which is described according to the invention, it is possible to carry out polymerization reactions or the modification of polymeric products to the desired degree of conversion or degree of modification by means of IR-ATR spectroscopy, without high technical expenditure and under accurately controlled conditions.

Procedure for the controlled production or modification of polymeric products by means of IR-ATR spectroscopy

The present invention relates to a process for the preparation of partially hydrogenated acrylonitrile-butadiene rubber in a pressurised reactor by hydrogenation of acrylonitrile-butadiene rubber by means of homogeneous or heterogeneous catalysis, in which the reactor contents are rendered inert before commencement of the hydrogenation, the Raman spectra of the reactor contents are recorded at short time intervals and the actual degree of hydrogenation of the product is determined from the intensities of the Raman emission lines and, on attainment of the required degree of hydrogenation, the reaction is arrested by suitable means.

Process for the preparation of partially hydrogenated acrylonitrile-butadiene rubbers (HNBR) with on-line application of Raman spectroscopy

This invention relates to a process for monitoring polycondensation or polyaddition reactions by measuring the OH, NH or NCO value or acid value of participating reactants by means of infra-red ATR spectroscopy of the associated, temperature-dependent absorption bands and compensating for the temperature dependence by calibrating the self-absorption of the ATR measuring crystal.

Process for monitoring polycondensation or polyaddition reactions

The invention relates to low-viscosity polyarylene sulfides (PAS), preferably polyphenylene sulfides (PPS), which are produced with cycloaliphatic, unsaturated acids as molecular weight regulators.

Low-viscosity polyarylene sulfides

The invention relates to a mixture of PPS and colophony which shows improved color stability during processing at high temperatures.

Color-stabilizing polyarylene sulfide mixture

This is invention relates to thermoplastic compositions of polyphenylene sulphide with an addition of silver nitrate which have improved crystallization properties and to a process for their preparation.

Polyphenylene sulphide composition containing silver nitrate

The invention relates to a process for the analysis of plastic mixtures by infrared transmission spectroscopy in which the spectra are run while the samples are rotated. This measure improves the accuracy and reproducibility of the spectra and, hence, the determination of individual components of the plastic mixture.

Spectroscopic analysis process for plastic mixtures

Optical fibres, and a process for their production, are described which comprise tubular plastic cladding and a core of a polymer whose refractive index is at least 1% greater than that of the cladding material. The core is obtained from a polymerisable mixture which comprises compounds containing epoxy groups, of which at least 10% by weight are siloxanes containing epoxy groups.

Optical fibers, and a process for their production

Growing community of inventors

Kempen, Germany

Udo Wolf