Inventor · Pittsfield, MA, US

Norman Johnson

15Patents
8h-index
41Co-inventors
72Inventor score

Filing activity: Nov 15, 1985 → Apr 19, 2017

Most-cited inventions

PatentTitleAreaCited byStatus
US4652685A Hydrogenation of lactones to glycols Chemistry; Metallurgy 99 Expired
US6630568B1 Method for purification of aromatic polyethers Chemistry; Metallurgy 36 Expired
US6251354A Process for recovering sodium nitrite Chemistry; Metallurgy 31 Expired
US6949622B2 Method of separating a polymer from a solvent Performing Operations; Transporting 23 Expired
US7115785B2 Method for making salts hydroxy-substituted hydrocarbons Chemistry; Metallurgy 19 Expired
US6790934B2 Method for purification of aromatic polyethers Chemistry; Metallurgy 19 Expired
US7714095B2 Phase transfer catalyzed method for preparation of polyetherimides Chemistry; Metallurgy 13 Active
US7125954B2 Method for producing polyether polymers Chemistry; Metallurgy 13 Expired
US7122619B2 Method of separating a polymer from a solvent Performing Operations; Transporting 8 Expired
US8372941B2 Method for purification of polyether polymers and mixtures resulting therefrom Chemistry; Metallurgy 6 Active
US9181395B2 Optimized emulsion drying process for making micronized polyetherimide polymers Emerging Cross-Sectional Technologies 5 Active
US5030773A Process for the production of butanediol Chemistry; Metallurgy 3 Expired
US10407397B2 Method for isolation of a dianhydride and dianhydrides prepared by the method Chemistry; Metallurgy 3 Active
US8592548B2 Method to prepare bis(haloimides) Chemistry; Metallurgy 0 Expired
US8729214B2 Mixtures resulting from methods for purification of polyether polymers Chemistry; Metallurgy 0 Active

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