Issued Patents All Time
Showing 1–25 of 43 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5578711 | Process for the preparation of dyestuffs | Alfred Brack, Karl-Heinrich Lange | 1996-11-26 |
| 5541299 | Process for the preparation of dyestuffs | Alfred Brack, Karl-Heinrich Lange | 1996-07-30 |
| 5502171 | Process for the preparation of dyestuffs | Alfred Brack, Karl-Heinrich Lange | 1996-03-26 |
| 5328993 | Cationic triazatrimethine dyestuffs | Hauke Furstenwerth, Karl-Heinrich Lange, Alfred Brack | 1994-07-12 |
| 5292881 | New naphthalimides, toners containing these and the use of the new naphthalimides as additives for toners | Horst Berneth, Horst Harnisch, Jurgen-Rolf Hassdenteufel, Matthias Kocher | 1994-03-08 |
| 5233048 | Triarylmethane color formers | Udo Eckstein | 1993-08-03 |
| 5208341 | Carbonylaminostyryls | Karin Hassenruck | 1993-05-04 |
| 5030612 | Thermal dye sublimation transfer recording element | Herman Uytterhoeven, Siegfried Korte | 1991-07-09 |
| 5013627 | Electrophotographic toners with cationic charge increasing additive | Horst Harnisch | 1991-05-07 |
| 5013857 | Process for the preparation of sulpho-free triphenyl-methane dyestuffs | Horst Berneth | 1991-05-07 |
| 4997740 | Electrophotographic toners with substituted 3-amino-1-imino-isoindolenine salts | Horst Harnisch, Klaus Wunderlich | 1991-03-05 |
| 4927729 | Colorless salts of heteropolyacids as charge control substances in toners | Horst Harnisch | 1990-05-22 |
| 4897223 | Tri-phenyl methyl color-forming agents | Udo Eckstein, Hubertus Psaar | 1990-01-30 |
| 4869989 | Dry toners containing fanal pigments based on cationic dyes | Hubertus Psaar | 1989-09-26 |
| 4849306 | Dry toners containing methinefanal pigments | Hubertus Psaar, Horst Berneth | 1989-07-18 |
| 4847177 | Fanal pigments of closed-ring dry toners containing indamine-and diphenylmethane dyestuffs | Hubertus Psaar | 1989-07-11 |
| 4841052 | Naphthalic acid imides electrophotographic toners | Horst Harnisch | 1989-06-20 |
| 4812379 | Electrophotographic toners containing an additive reinforcing the cationic charge | Horst Harnisch | 1989-03-14 |
| 4808719 | 1H-imidazo[2,3-a]indol-2-ones as color-forming agents | Hubertus Psaar | 1989-02-28 |
| 4760132 | Process for preparing cationic hydrazone dyestuffs | Hans-Lothar Dorsch, Dietmar Kalz, Volker Huhne | 1988-07-26 |
| 4710569 | Basic dyestuffs | Gunter Franke, Dieter Ockelmann, Peter Wild | 1987-12-01 |
| 4670882 | Dyestuff laser | Helmut Telle, Rudolf Schieder, Udo Eckstein | 1987-06-02 |
| 4600776 | Cationic enamine dyestuff indolylmethine derivatives | Karlheinrich Meisel | 1986-07-15 |
| 4551265 | Fluorescent dyestuffs, processes for their preparation and their use as laser dyestuffs | Wolfgang Brinkwerth, Wolfgang Huffer, Rudolf Schieder, Helmut Telle | 1985-11-05 |
| 4542224 | Process for preparing cationic methine dyestuffs | Hans-Peter Kuhlthau | 1985-09-17 |