Shpp Global Technologies B.v.

Sabic Global Technolgoies B.v.

Sivakumar Periyasamy

Hareesh Shamrao Deshpande

Robert John Werling

Gregory L Hemmer

Ravi Gautam

Thomas Link Guggenheim

Surya Prakasa Rao Daliparthi

Bernabe Quevedo Sanchez

Juan J Rodriguez Ordonez

Javier Nieves Remacha

Siva Kumar Sreeramagiri

Maria Patricia Forcen Jimenez

Sunil S Dhumal

Simon Padmanabhan

Srinivas Mahesh Kumar

Jose Roman Galdamez

Aaron Matthew Royer

Jorge Jimenez Umana

A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a single packed extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Method for isolation of an aromatic dianhydride and aromatic dianhydrides prepared by the method

A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent in a first extractor for a first time period, at a first extraction temperature and subsequent to the first time period, extracting the aqueous reaction mixture with an organic solvent in a second extractor for a second time period, at a second extraction temperature. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Method for isolation of a dianhydride and dianhydrides prepared by the method

A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Process to make low color polyetherimide by halo-displacement and low color polyetherimide

A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

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Karnataka, India

Sivakumar Periyasamy