Norbert Maak
21Patents
6h-index
12Co-inventors
58Inventor score
Filing activity: Nov 6, 1980 → Aug 26, 1988
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4685931A | Acrylate dispersion and its use for thickening hydrogen peroxide preparations | Chemistry; Metallurgy | 20 | Expired |
| US4341559A | Binders based upon solutions of alkali metal silicates | Chemistry; Metallurgy | 14 | Expired |
| US4976742A | META-aminophenols useful as oxidation hair dye couplers | Human Necessities | 14 | Expired |
| US4745652A | New tetra-aminopyrimidine derivatives and their use in hair-dyeing preparations | Chemistry; Metallurgy | 14 | Expired |
| US4487607A | Oxidation hair dyes containing 5-halo-2,3-pyridine-diols as coupler components | Human Necessities | 10 | Expired |
| US4838893A | Oxidation hair dyes comprising substituted dihydroxypyridines as coupling components | Human Necessities | 8 | Expired |
| US4619666A | Hair dyes containing amino-nitrobenzoic acid or amino-nitrobenzene sulfonic acids as substantive dyes | Chemistry; Metallurgy | 6 | Expired |
| US4842612A | Aminophenyl alkylenediamines useful in oxidation hair dyes | Human Necessities | 6 | Expired |
| US4900325A | Hair-dyeing preparations | Human Necessities | 6 | Expired |
| US4541869A | Process for forming foundry components | Chemistry; Metallurgy | 5 | Expired |
| US4784667A | Oxidation hair dyes comprising diamino-substituted pyridines and amino-substituted aromatics as precursors | Human Necessities | 5 | Expired |
| US4698066A | Amine oxidation dye hair treating compositions | Human Necessities | 4 | Expired |
| US4402699A | Coupler components for the oxidation of hair dyes and their use, as well as hair dyeing agents containing them | Human Necessities | 3 | Expired |
| US4371370A | Oxidation hair dyes comprising bis-(2,4-diaminophenoxy)-alkanols as coupling components | Chemistry; Metallurgy | 2 | Expired |
| US4859206A | Hair dye preparations containing nitrodiphenylamine derivative | Human Necessities | 2 | Expired |
| US4832697A | Hair dye preparations containing substantive nitrodiphenylamine derivatives | Human Necessities | 2 | Expired |
| US4756716A | Preparations containing substantive nitrodiphenylamine derivative hair dyes | Human Necessities | 2 | Expired |
| US4684371A | Oxidation hair dyes comprising m-phenylenediamine derivatives as coupling components | Chemistry; Metallurgy | 2 | Expired |
| US4756715A | Hair-dyeing preparations containing substantive nitrodiphenylamine derivatives | Human Necessities | 1 | Expired |
| US4552565A | Hair dyes: diresorcyl sulphide, sulphoxide or sulphone coupling agents | Human Necessities | 1 | Expired |
| US4900327A | Preparations containing substantive nitrodiphenylamine derivative hair dyes | Human Necessities | 0 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.