Hubertus Psaar
30Patents
7h-index
14Co-inventors
62Inventor score
Filing activity: May 10, 1974 → Oct 31, 1990
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5130442A | Chromogenic enamine compounds, their preparation and use as color formers | Chemistry; Metallurgy | 31 | Expired |
| US4783196A | Highly concentrated stable solutions of color-forming agents: for pressure-sensitive recording materials | Performing Operations; Transporting | 13 | Expired |
| US5094688A | Triarylmethane color-forming agents | Performing Operations; Transporting | 11 | Expired |
| US4923641A | Highly concentrated stable solutions of color-forming agent: for pressure-sensitive recording materials | Performing Operations; Transporting | 10 | Expired |
| US4458009A | Process for the production of color photographic images and photographic recording materials | Emerging Cross-Sectional Technologies | 10 | Expired |
| US4211436A | Pressure-sensitive recording material | Emerging Cross-Sectional Technologies | 9 | Expired |
| US4125717A | Process for the preparation of oxazine dyestuffs | Chemistry; Metallurgy | 7 | Expired |
| US4138570A | Indoline linked to 2-pyrazoline | Emerging Cross-Sectional Technologies | 7 | Expired |
| US3999939A | Transfer printing process | Emerging Cross-Sectional Technologies | 6 | Expired |
| US4869989A | Dry toners containing fanal pigments based on cationic dyes | Physics | 6 | Expired |
| US3992140A | Printing inks for transfer printing | Performing Operations; Transporting | 6 | Expired |
| US4897494A | Bis(indolyl)ethylene process | Chemistry; Metallurgy | 5 | Expired |
| US4931567A | Bis(indolyl)ethylene compounds | Chemistry; Metallurgy | 4 | Expired |
| US4897223A | Tri-phenyl methyl color-forming agents | Chemistry; Metallurgy | 4 | Expired |
| US3972879A | Process for isolating easily soluble basic oxazine dyestuffs and phenazine dyestuffs | Chemistry; Metallurgy | 3 | Expired |
| US4083680A | Printing inks for transfer printing | Textiles; Paper | 3 | Expired |
| US4600930A | Recording material which reacts under the influence of heat, its preparation and the use of acid-modified polymers as acceptors in this recording material | Performing Operations; Transporting | 3 | Expired |
| US4201707A | Methine dyestuffs containing a phenyl azo group | Chemistry; Metallurgy | 2 | Expired |
| US4087241A | Printing inks for transfer printing | Performing Operations; Transporting | 2 | Expired |
| US4847177A | Fanal pigments of closed-ring dry toners containing indamine-and diphenylmethane dyestuffs | Chemistry; Metallurgy | 2 | Expired |
| US5118814A | Tetraindolyl-heptamethine derivatives | Chemistry; Metallurgy | 1 | Expired |
| US4918048A | Thermoreactive recording material | Performing Operations; Transporting | 1 | Expired |
| US4849306A | Dry toners containing methinefanal pigments | Physics | 1 | Expired |
| US5134113A | Thermoreactive recording material | Performing Operations; Transporting | 1 | Expired |
| US4902806A | Bis(indolyl)ethylene aldehydes | Chemistry; Metallurgy | 1 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.