Inventor · disambiguated record
Friedhelm Steffens
Also filed as: STEFFENS FRIEDHELM
36 granted patents·9 pending applications·222 citations·filing 1986–2025
96Inventor score
Files withCOVESTRO DEUTSCHLAND AG20BAYER MATERIALSCIENCE AG11BAYER AG3BAYER MATERIALSCIENCE LLC3BISKUP KLAUS2
Top patents by PatentIndex Score
45 records- 0195US6719957B2Process for purification of anhydrous hydrogen chloride gasBAYER AG·Filed 2002·Granted Apr 13, 2004·89 cites·14 claims
- 0292US7615662B2Process for the preparation of isocyanates in the gas phaseBAYER MATERIALSCIENCE AG·Filed 2007·Granted Nov 10, 2009·14 cites·11 claims
- 0392US7118653B2Process for the purification of mixtures of toluenediisocyanate incorporating a dividing-wall distillation columnBAYER AG·Filed 2003·Granted Oct 10, 2006·41 cites·9 claims
- 0491US8563768B2Process for the preparation of isocyanatesBRUNS RAINER·Filed 2010·Granted Oct 22, 2013·10 cites·8 claims
- 0591US7541487B2Process for the preparation of isocyanates in the gas phaseBAYER MATERIALSCIENCE AG·Filed 2007·Granted Jun 2, 2009·11 cites·11 claims
- 0689US9024057B2Process for the preparation of isocyanates in the gas phaseBISKUP KLAUS·Filed 2009·Granted May 5, 2015·12 cites·14 claims
- 0786US8063241B2Process for the preparation of toluene-diisocyanateLORENZ WOLFGANG·Filed 2010·Granted Nov 22, 2011·5 cites·10 claims
- 0885US7645900B2Process for the preparation of isocyanatesBAYER MATERIALSCIENCE AG·Filed 2009·Granted Jan 12, 2010·7 cites·8 claims
- 0983US9840461B2Method for operating a gas-phase phosgenation plantCOVESTRO DEUTSCHLAND AG·Filed 2015·Granted Dec 12, 2017·2 cites·16 claims
- 1081US9480958B2Device and method for producing phosgeneBAYER MATERIALSCIENCE AG·Filed 2013·Granted Nov 1, 2016·5 cites·23 claims
- 1179US7511176B2Process for the preparation of toluenediamines by catalytic hydrogenation of dinitrotoluenesBAYER MATERIALSCIENCE AG·Filed 2007·Granted Mar 31, 2009·3 cites·5 claims
- 1277US9932299B2Process for separating an isocyanate prepared by phosgenation of a primary amine in the gas phase from the gaseous crude product of the phosgenationBAYER MATERIALSCIENCE AG·Filed 2014·Granted Apr 3, 2018·2 cites·14 claims
- 1374US10576392B2Distillation column and use thereof for cleaning isocyanatesCOVESTRO DEUTSCHLAND AG·Filed 2016·Granted Mar 3, 2020·1 cites·22 claims
- 1474US8399702B2Process for the production of aromatic diisocyanates in the gasPOHL FRITZ·Filed 2008·Granted Mar 19, 2013·2 cites·15 claims
- 1573US7322565B2Stirring device and process for carrying out a gas-liquid reactionBAYER MATERIALSCIENCE AG·Filed 2005·Granted Jan 29, 2008·3 cites·18 claims
- 1672US10676448B2Method for producing TDI-trimerisates with high purityCOVESTRO DEUTSCHLAND AG·Filed 2018·Granted Jun 9, 2020·0 cites·8 claims
- 1772US9029595B1Method for working up distillation residues from isocyanate productionBAYER MATERIALSCIENCE LLC·Filed 2013·Granted May 12, 2015·1 cites·9 claims
- 1871US9365503B2Process for the preparation of isocyanates in the gas phaseBISKUP KLAUS·Filed 2009·Granted Jun 14, 2016·2 cites·9 claims
- 1969US8030522B2Process for the production of toluene diisocyanateBAYER MATERIALSCIENCE LLC·Filed 2006·Granted Oct 4, 2011·2 cites·6 claims
- 2069US2024336554A1Method for the Removal of Water from and Transport of Aliphatic DiaminesCOVESTRO DEUTSCHLAND AG·Filed 2022·Application pending·0 cites
- 2167US10189945B2Method for producing light-coloured TDI-polyisocyanatesCOVESTRO DEUTSCHLAND AG·Filed 2014·Granted Jan 29, 2019·0 cites·11 claims
- 2267US9376377B2Method for producing isocyanatesCOVESTRO DEUTSCHLAND AG·Filed 2014·Granted Jun 28, 2016·1 cites·9 claims
- 2364US10131641B2Method for producing TDI-trimerisates with high purityBAYER MATERIALSCIENCE AG·Filed 2014·Granted Nov 20, 2018·0 cites·9 claims
- 2463US2024343674A1Obtaining Aliphatic Amines from CompositionsCOVESTRO DEUTSCHLAND AG·Filed 2022·Application pending·0 cites
- 2562US2025206694A1Method for the purification of anilineCOVESTRO DEUTSCHLAND AG·Filed 2025·Application pending·0 cites
- 2659US10011484B1Process for purifying raw-material gases by fractionationCOVESTRO DEUTSCHLAND AG·Filed 2018·Granted Jul 3, 2018·0 cites·8 claims
- 2756US2024101783A1Process for recovering raw materials from polyurethane foamsCOVESTRO DEUTSCHLAND AG·Filed 2021·Application pending·0 cites
- 2855US2022348533A1Method for the purification of anilineCOVESTRO INTELLECTUAL PROPERTY GMBH & CO KG·Filed 2020·Application pending·0 cites
- 2954US9938147B2Process for purifying raw-material gases by fractionationCOVESTRO DEUTSCHLAND AG·Filed 2013·Granted Apr 10, 2018·0 cites·10 claims
- 3054US2008146835A1Process for the preparation of toluene-diisocyanateBAYER MATERIALSCIENCE AG·Filed 2007·Application pending·0 cites
- 3153US2006277094A1Data processing system and method for regulating an installationKIRSCH JURGEN·Filed 2006·Application pending·0 cites
- 3252US9688619B2Process for obtaining organic isocyanates from distillation residues from isocyanate preparationCOVESTRO DEUTSCHLAND AG·Filed 2014·Granted Jun 27, 2017·0 cites·15 claims
- 3351US2010160673A1Process for the preparation of isocyanates in the gas phaseBAYER MATERIALSCIENCE AG·Filed 2009·Application pending·0 cites
- 3449US10889539B2Aniline purification processCOVESTRO DEUTSCHLAND AG·Filed 2019·Granted Jan 12, 2021·0 cites·15 claims
- 3549US7555917B2Process for purification of anhydrous hydrogen chloride gasBAYER MATERIALSCIENCE LLC·Filed 2004·Granted Jul 7, 2009·1 cites·1 claims
- 3648US10894222B2Distributor device, in particular for falling film evaporators, and use thereofCOVESTRO DEUTSCHLAND AG·Filed 2018·Granted Jan 19, 2021·0 cites·17 claims
- 3748US2023357532A1Method for recovering raw materials from polyurethane productsCOVESTRO DEUTSCHLAND AG·Filed 2021·Application pending·0 cites
- 3845US12187858B2Method for recovering raw materials from polyurethane productsCOVESTRO DEUTSCHLAND AG·Filed 2020·Granted Jan 7, 2025·0 cites·15 claims
- 3943US10435353B2Method for producing isocyanatesCOVESTRO DEUTSCHLAND AG·Filed 2016·Granted Oct 8, 2019·0 cites·16 claims
- 4043US10143987B2Method for dividing fluid streamsKEGGENHOFF BERTHOLD·Filed 2009·Granted Dec 4, 2018·0 cites·9 claims
- 4142US10239826B2Method for producing isocyanatesCOVESTRO DEUTSCHLAND AG·Filed 2016·Granted Mar 26, 2019·0 cites·16 claims
- 4241US4732685AMethod of liquid-liquid extraction using material exchange columnsBAYER AG·Filed 1986·Granted Mar 22, 1988·7 cites·7 claims
- 4339US11267703B2Method and a system for separating and treating impurities from a hydrogen chloride liquid mixtureCOVESTRO DEUTSCHLAND AG·Filed 2017·Granted Mar 8, 2022·0 cites·16 claims
- 4438US7575660B2Process for the distillative separation of aqueous amine solutionsBAYER MATERIALSCIENCE AG·Filed 2005·Granted Aug 18, 2009·1 cites·9 claims
- 4536US9845286B2Process for operating a gas phase phosgenation plantCOVESTRO DEUTSCHLAND AG·Filed 2015·Granted Dec 19, 2017·0 cites·18 claims
Join the waitlist — get patent alerts
Get an alert when Friedhelm Steffens files or is granted a new patent.
We store only your email — no account needed. See our privacy policy.
Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →