Inventor · Ludwigshafen, DE

Tom Witzel

47Patents
11h-index
75Co-inventors
74Inventor score

Filing activity: Apr 14, 1989 → Dec 9, 1998

Most-cited inventions

PatentTitleAreaCited byStatus
US5527946A Preparation of aliphatic alpha, omega-aminonitriles Chemistry; Metallurgy 31 Expired
US5489663A Preparation of polyisocyanates containing isocyanurate groups and use thereof Chemistry; Metallurgy 26 Expired
US5663444A Preparation of a pure dialkylaminoethanol stable against discoloration Chemistry; Metallurgy 20 Expired
US5696048A Cobalt catalysts Chemistry; Metallurgy 17 Expired
US6201160A Preparation of alcohols Chemistry; Metallurgy 17 Expired
US5646277A Preparation of caoprolactam Chemistry; Metallurgy 16 Expired
US5463130A Preparation of peralkylated amines Chemistry; Metallurgy 14 Expired
US5536691A Cobalt catalysts and a process required for their preparation Chemistry; Metallurgy 14 Expired
US6018074A Process for the preparation of polyalcohols Chemistry; Metallurgy 13 Expired
US5371292A Preparation of 3-aminomethyl-3,5,5-trimethyl-cyclohexylamine Chemistry; Metallurgy 12 Expired
US5495014A Preparation of caprolactam Chemistry; Metallurgy 12 Expired
US5739324A Preparation of caprolactam Chemistry; Metallurgy 11 Expired
US5756845A Preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine Chemistry; Metallurgy 9 Expired
US5717090A Simultaneous preparation of caprolactam and hexamethylenediamine Chemistry; Metallurgy 8 Expired
US5728317A Polyisocyanate compositions having a long shelf life and obtainable by phosgene-free methods, their preparation and their use Chemistry; Metallurgy 7 Expired
US6166207A Preparation of bicyclic amidines and diazacycloalkenes Chemistry; Metallurgy 7 Expired
US5557011A Preparation of diamines Chemistry; Metallurgy 6 Expired
US6022999A Preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine having a cis/trans isomer ratio of at least 70:30 Chemistry; Metallurgy 6 Expired
US5166443A Preparation of 2,2-disubstituted pentane-1,5-diamines Chemistry; Metallurgy 5 Expired
US5239120A Preparation of 2-(3-aminopropyl)-cycloalkylamines Chemistry; Metallurgy 5 Expired
US5840981A Process for producing N-methyl-2(3,4 dimethoxyphenyl)-ethylamine Performing Operations; Transporting 4 Expired
US5565583A Preparation of 2-substituted but-2-ene-1, 4-dial-4-acetals and novel hemiacetals of glyoxal monoacetals Chemistry; Metallurgy 4 Expired
US5481037A Decontamination of tertiary amines from primary and secondary amines Chemistry; Metallurgy 4 Expired
US5684201A Preparation of aliphatic and cycloaliphatic oximes Chemistry; Metallurgy 4 Expired
US5917080A Preparation of 2-cyano-3,3-diarylacrylic esters Chemistry; Metallurgy 3 Expired

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