Patent Leaderboard
USPTO Patent Rankings Data through Sept 30, 2025
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Ulrich Riegel — 65 Patents

Basf Se: 34 patents #286 of 13,826Top 3%
CACassella Aktiengesellschaft: 21 patents #8 of 243Top 4%
Hoechst Gmbh: 4 patents #925 of 4,020Top 25%
The Procter & Gamble: 3 patents #3,571 of 10,133Top 40%
DIDresser Industries: 2 patents #157 of 787Top 20%
SHSociete Francaise Hoechst: 1 patents #26 of 69Top 40%
SCSwiss Reinsurance Company: 1 patents #41 of 164Top 25%
Landstuhl, DE: #1 of 17 inventorsTop 6%
Overall (All Time): #33,942 of 4,157,543Top 1%
65 Patents All Time

Issued Patents All Time

Showing 51–65 of 65 patents

Patent #TitleCo-InventorsDate
5274048 Use of glycidyl phosphonates as crosslinkers in the preparation of hydrogels Fritz Engelhardt, Hanss-Jerg Kleiner, Wolf-Dieter Muller 1993-12-28
5258448 Absorbent polymers, manufacturing process and their use in particular for sanitary articles Paul Mallo, Fritz Engelhardt, Rüdiger Funk 1993-11-02
5068298 Alkenyl-phosphonic and -phosphinic esters, process for their preparation, their use and hydrogels prepared using them Friedrich Engelhardt, Joachim Gersdorf, Hans-Jerg Kleiner 1991-11-26
5066745 Alkenylphosphonic and --phosphinic acid esters, process for their preparation, hydrogels produced using them, and their use Friedrich Engelhardt, Joachim Gersdorf, Hans-Jerg Kleiner 1991-11-19
5041496 Hydrophilic, swellable graft copolymers, their preparation and use Friedrich Engelhardt, Jurgen Kuhlwein 1991-08-20
5011892 Hydrophilic swellable graft copolymers, their preparation and use Friedrich Engelhardt 1991-04-30
4959441 Alkenylphosphonic and -phosphinic acid esters, process for their preparation, hydrogels produced using them, and their use Friedrich Engelhardt, Joachim Gersdorf, Hans-Jerg Kleiner 1990-09-25
4828570 Tanning agent and a process for its preparation Fritz Engelhardt, Kuno Reh, Helmut Croon, Hermann Becker, Werner Lotz 1989-05-09
4749758 Process for the preparation of copolymers of vinylphosphonic acid and (meth) acrylic acid in aqueous solution Walter Dursch, Jurgen Grosse, Werner Gohla, Friedrich Engelhardt 1988-06-07
4587283 Cement slurries for deep holes, with a copolymer content for reducing the water loss Martin Hille, Wolfgang Friede, Heinz Wittkus, Friedrich Engelhardt 1986-05-06
4551513 Water soluble copolymers Friedrich Engelhardt, Klaus Kuhlein, Sigmar-Peter von Halasz, Jeffery C. Dawson, Anthony R. Reed 1985-11-05
4500437 Water soluble copolymers for use in fracture-acidizing of wells Friedrich Engelhardt, Klaus Kuhlein, Sigmar-Peter von Halasz, Jeffery C. Dawson, Anthony R. Reed 1985-02-19
4378446 Acrylate-modified melamine resin which is stable on storage, its preparation and its use Wilhelm Adam, Curt A. Wagner, Renate Konrad, Friedrich Engelhardt, Georg W. Eckhardt +1 more 1983-03-29
4357245 Water-soluble copolymer and its preparation Friedrich Engelhardt, Martin Hille, Heinz Wittkus 1982-11-02
4309523 Water-soluble copolymer of acrylamidomethylpropanesulfonic acids salts Friedrich Engelhardt, Martin Hille, Heinz Wittkus 1982-01-05