Issued Patents All Time
Showing 1–19 of 19 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5134113 | Thermoreactive recording material | Gunter Klug, Siegfried Korte | 1992-07-28 |
| 5130442 | Chromogenic enamine compounds, their preparation and use as color formers | Karlheinrich Meisel | 1992-07-14 |
| 5118814 | Tetraindolyl-heptamethine derivatives | Horst Berneth, Gunter Klug | 1992-06-02 |
| 5094688 | Triarylmethane color-forming agents | Udo Eckstein, Gert Jabs | 1992-03-10 |
| 4931567 | Bis(indolyl)ethylene compounds | Horst Berneth | 1990-06-05 |
| 4923641 | Highly concentrated stable solutions of color-forming agent: for pressure-sensitive recording materials | Udo Eckstein | 1990-05-08 |
| 4918048 | Thermoreactive recording material | Siegfried Korte | 1990-04-17 |
| 4902806 | Bis(indolyl)ethylene aldehydes | — | 1990-02-20 |
| 4897494 | Bis(indolyl)ethylene process | Horst Berneth | 1990-01-30 |
| 4897223 | Tri-phenyl methyl color-forming agents | Udo Eckstein, Roderich Raue | 1990-01-30 |
| 4869989 | Dry toners containing fanal pigments based on cationic dyes | Roderich Raue | 1989-09-26 |
| 4849306 | Dry toners containing methinefanal pigments | Roderich Raue, Horst Berneth | 1989-07-18 |
| 4847177 | Fanal pigments of closed-ring dry toners containing indamine-and diphenylmethane dyestuffs | Roderich Raue | 1989-07-11 |
| 4808719 | 1H-imidazo[2,3-a]indol-2-ones as color-forming agents | Roderich Raue | 1989-02-28 |
| 4783196 | Highly concentrated stable solutions of color-forming agents: for pressure-sensitive recording materials | Udo Eckstein | 1988-11-08 |
| 4600930 | Recording material which reacts under the influence of heat, its preparation and the use of acid-modified polymers as acceptors in this recording material | — | 1986-07-15 |
| 4458009 | Process for the production of color photographic images and photographic recording materials | Edith Weyde, Wilhelm Saleck, Anita von Konig, Hans hlschlager | 1984-07-03 |
| 4211436 | Pressure-sensitive recording material | Hans-Peter Kuhlthau, Roderich Raue | 1980-07-08 |
| 4201707 | Methine dyestuffs containing a phenyl azo group | — | 1980-05-06 |