Derek Walker
35Patents
7h-index
28Co-inventors
69Inventor score
Filing activity: Jul 9, 1973 → Jul 13, 2020
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4347354A | Preparation of 1-N-[.omega.-amino-.alpha.-hydroxyalkanoyl]aminoglycoside polysilylated antibiotics and products obtained therefrom | Emerging Cross-Sectional Technologies | 30 | Expired |
| US4424343A | Preparation of 1-N-.omega.-amino-.alpha.-hydroxyalkanoyl!kanamycin polysilylates and products | Chemistry; Metallurgy | 15 | Expired |
| US4340344A | Apparatus for manufacture of thermoplastics pipe | Performing Operations; Transporting | 11 | Expired |
| US6699802B1 | Fire resistant textile material | Emerging Cross-Sectional Technologies | 11 | Expired |
| US6955193B2 | Fire resistant textile material | Emerging Cross-Sectional Technologies | 10 | Expired |
| US4038469A | Aqueous insoluble polymers containing a plurality of diazomethylene groups | Chemistry; Metallurgy | 10 | Expired |
| US4076913A | Solid or gel polymers containing a plurality of free hydrazone groups | Chemistry; Metallurgy | 7 | Expired |
| US4322347A | 2-Carbamoyloxymethyl-penicillin derivatives | Emerging Cross-Sectional Technologies | 6 | Expired |
| US4310459A | Process for producing carbamoyl substituted penams and carbamoyl substituted cephams from penicillin sulfoxide esters | Chemistry; Metallurgy | 5 | Expired |
| US4813114A | Machining the ends of round bar and tube and similiar workpieces | Emerging Cross-Sectional Technologies | 5 | Expired |
| US4176131A | Chemical process | Chemistry; Metallurgy | 4 | Expired |
| US4223135A | Production of cephalosporins | Chemistry; Metallurgy | 4 | Expired |
| US4790061A | Machining the ends of lengths of wire and bar and similar workpieces | Emerging Cross-Sectional Technologies | 4 | Expired |
| US4634322A | Assembly for use in removing material from the ends of bars or the like workpieces | Emerging Cross-Sectional Technologies | 4 | Expired |
| US5571910A | Process for the preparation of intermediates useful in the synthesis of cephalosporins | Emerging Cross-Sectional Technologies | 3 | Expired |
| US4059573A | Extraction of N-blocked amino acids from aqueous media | Chemistry; Metallurgy | 3 | Expired |
| US4374982A | Cepham compounds | Chemistry; Metallurgy | 3 | Expired |
| US5660711A | Process for the preparation of intermediates useful in the synthesis of cephalosporins | Emerging Cross-Sectional Technologies | 2 | Expired |
| US4426520A | 3-Carbamoyloxy-cepham-4-carboxylic acid derivatives | Chemistry; Metallurgy | 2 | Expired |
| US4518773A | """3-Carbamoyloxy cephalosporins""" | Chemistry; Metallurgy | 2 | Expired |
| US4316017A | Cephalosporin intermediates | Chemistry; Metallurgy | 2 | Expired |
| US4351766A | Production of penicillins | Chemistry; Metallurgy | 2 | Expired |
| US4316016A | Cephalosporin intermediates | Chemistry; Metallurgy | 1 | Expired |
| US4083837A | Oxidation of hydrazones to the corresponding diazo compound | Chemistry; Metallurgy | 1 | Expired |
| US4323535A | Manufacture of thermoplastics pipe | Performing Operations; Transporting | 1 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.