Process for the preparation of partially hydrogenated acrylonitrile-butadiene rubbers (HNBR) with on-line application of Raman spectroscopy
AssigneeBayer Aktiengesellschaft
InventorsDieter Brück, Udo Wolf
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Abstract
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.
Claims17
A process for the preparation of partially hydrogenated acrylonitrile-butadiene rubber (HNBR) in a pressurized reactor by hydrogenation of acrylonitrile-butadiene rubber (NBR) by means of homogeneous or heterogeneous catalysis using a Raman spectrometer to measure Raman spectra of the reactor contents, the process comprising the steps of:
- a) charging the reactor with reactants;
- b) hydrogenating the NBR in the presence of the catalyst;
- c) recording the Raman spectra of the reactor contents at short time intervals using a pressure-resistant inspection glass attached to the reactor to carry out a Raman effect, the Raman effect carried out by passing au exciting light through the inspection glass into the reaction solution and observing the Raman scattering;
- d) determining a degree of hydrogenation from the intensities of the Ramnan emission lines;
- and e) arresting the reaction upon attainment of a required degree of hydrogenation;
- wherein the reactor contents are rendered inert before commencement of the hydrogenation by removing oxygen from the reactor.
A process for preparing a partially hydrogenated acrylonitrile-butadiene rubber (HNBR), the process comprising the steps of:
- a) charging a reactor with reactants,
- b) rendering the reactor contents inert before commencing hydrogenation by removing oxygen from the reactor,
- c) pressurizing the reactor,
- d) hydrogenating acrylonitrile-butadiene rubber (NBR) in the presence of a homogeneous or heterogeneous catalyst,
- e) recording Raman spectra of the reactants at short time intervals using a pressure-resistant inspection glass to the reactor to carry out a Raman effect, the Raman effect carried out by passing an exciting light through the inspection glass into the reactor contents and observing the Raman scattering,
- f) determining a degree of hydrogenation of the HNBR product from intensities of the Raman emission lines, and
- g) arresting the hydrogenation reaction after a required degree of hydrogenation is achieved.
Dependencies are inferred from the claim text.