Issued Patents 1989
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4859206 | Hair dye preparations containing nitrodiphenylamine derivative | David Rose, Horst Hoeffkes, Norbert Maak | 1989-08-22 |
| 4842612 | Aminophenyl alkylenediamines useful in oxidation hair dyes | David Rose, Norbert Maak | 1989-06-27 |
| 4838893 | Oxidation hair dyes comprising substituted dihydroxypyridines as coupling components | David Rose, Norbert Maak | 1989-06-13 |
| 4832697 | Hair dye preparations containing substantive nitrodiphenylamine derivatives | David Rose, Norbert Maak | 1989-05-23 |
| 4828568 | Oxidation hair-dyeing preparations | Guenther Konrad, Hinrich Moeller | 1989-05-09 |