Patents by Inventor Arun Satyanarayana Kumar

Arun Satyanarayana Kumar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Methods for producing and purifying 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine compounds, the purified monomers, and polymers derived therefrom
    Patent number: 9340502
    Abstract: Disclosed herein is a method for producing a purified 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine of formula (I) wherein R1 is hydrogen or a C1-25 hydrocarbyl group and R2 is a hydrogen, a C1-25 hydrocarbyl group, or a halogen, and wherein the method comprises dissolving a crude phthalimidine compound in an aqueous base solution; precipitating the dissolved, crude phthalimidine compound from the aqueous base solution by adding an acid in an amount effective to lower the pH of the solution to 9.0 to 12.0, to provide a semicrude phthalimidine compound; and isolating the semicrude phthalimidine compound from the aqueous base solution, to provide the purified 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine of formula (I), and having a phenolphthalein compound content of less than 2,500 ppm, based on the weight of the purified 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine.
    Type: Grant
    Filed: August 18, 2014
    Date of Patent: May 17, 2016
    Assignee: SABIC GLOBAL TECHNOLOGIES B.V.
    Inventors: Venkata Rama Narayanan Ganapathy Bhotla, Balakrishnan Ganesan, Kishan Gurram, Salkod Parameshwar Mallika, Arun Satyanarayana Kumar, Shubashree Swaminathan