Inventor · disambiguated record
Masafumi Umekawa
Also filed as: UMEKAWA MASAFUMI
6 granted patents·17 citations·filing 2007–2012
77Inventor score
Top patents by PatentIndex Score
6 records- 0182US7709172B2Oxidized mixed cyclic phenol sulfides, and charge control agents and toners using the sameHODOGAYA CHEMICAL CO LTD·Filed 2008·Granted May 4, 2010·6 cites·8 claims
- 0277US7901858B2Mixed cyclic phenol sulfides, and charge control agents and toners using the sameHODOGAYA CHEMICAL CO LTD·Filed 2008·Granted Mar 8, 2011·5 cites·3 claims
- 0376US7820832B2Oxidized mixed cyclic phenol sulfides, and charge control agents and toners using the sameHODOGAYA CHEMICAL CO LTD·Filed 2009·Granted Oct 26, 2010·4 cites·8 claims
- 0475US8232429B2Methods for producing oxidized cyclic phenol sulfidesYASUMURA MASATERU·Filed 2009·Granted Jul 31, 2012·2 cites·12 claims
- 0554US8624065B2Methods for producing oxidized cyclic phenol sulfidesYASUMURA MASATERU·Filed 2012·Granted Jan 7, 2014·0 cites·14 claims
- 0648US8263786B2Methods for producing cyclic phenol sulfidesYASUMURA MASATERU·Filed 2007·Granted Sep 11, 2012·0 cites·6 claims
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Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →