Inventor

Hellmut Kast

13Patents
3h-index
15Co-inventors
57Inventor score

Filing activity: Jan 24, 1974 → Aug 14, 2001

Most-cited inventions

PatentTitleAreaCited byStatus
US4147604A Photopolymerizable binders containing diaminobenzophenones Emerging Cross-Sectional Technologies 11 Expired
US4223144A Triphenylmethane dyes Textiles; Paper 11 Expired
US4000135A Manufacture of basic dyes by catalytic oxidation Performing Operations; Transporting 6 Expired
US3931182A Lactones of the diazaxanthene series, their production and their use as dye-forming components for copying methods Performing Operations; Transporting 3 Expired
US4976744A Preparation of concentrated solutions of cationic dyes as mono-carboxylates in glycol ether Emerging Cross-Sectional Technologies 3 Expired
US4052398A Diazarhodamine-lactones, their manufacture and their use as dye intermediates for copying processes Performing Operations; Transporting 3 Expired
US4176229A Basic dyes Chemistry; Metallurgy 3 Expired
US5073634A Tetrachloroferrates of basic dyes Textiles; Paper 2 Expired
US3946017A Lactones of the benzaxanthere series and dye-forming components for use in duplication processes Performing Operations; Transporting 2 Expired
US6846956B2 Triarylmethane dyes Emerging Cross-Sectional Technologies 1 Expired
US3997541A Lactones of the benzazaxanthene series and dye-forming components for duplication processes Chemistry; Metallurgy 1 Expired
US6160169A Preparation of amine salts of 4-nitrotoluene-2-sulfonic acid Chemistry; Metallurgy 1 Expired
US5892105A Preparation of amine salts of 4-nitrotoluene-2-sulfonic acid Chemistry; Metallurgy 0 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.