Sabic Innovative Plastics IP B.v.

Kumar Arun Satyanarayana

Balakrishnan Ganesan

Venkata Rama Narayanan Ganapathy Bhotla

Pradeep Jeevaji Nadkarni

Gurram Kishan

Salkod Parameshwar Mallika

Ravindra Vikram Singh

Kishan Gurram

Swaminathan Shubashree

Suresh Shanmugam

Suresh Shanumgam

Disclosed is a method for producing a purified 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine of formula (I) wherein Ris hydrogen or a Chydrocarbyl group and Ris a hydrogen, a Chydrocarbyl 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. Subsequent trituration with aqueous methanol and recrystallization from isopropanol can result in product having undetectable levels of phenolphthalein derivatives.

Methods for producing and purifying 2-aryl-3,3-bis(4-hydroxyaryl)phthalimidine compounds, the purified monomers, and polymers derived therefrom

Disclosed herein is a method for producing a purified 2-aryl-3,3-bis(4-hydroxyaryl) phthalimidine of formula (I) wherein Ris hydrogen or a Chydrocarbyl group and Ris a hydrogen, a Chydrocarbyl 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. Subsequent trituration with aqueous methanol and recrystallization from isopropanol can result in product having levels of phenolphthalein derivatives that are not detectable.

A method for purifying a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine comprises contacting a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a purification agent, removing a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound from the crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine, and producing a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising less than 200 parts per million of the 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound. The purification agent is selected from the group consisting of an acidic material, an organic acid chloride, an organic anhydride, or a combination thereof. The 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound has a formula: wherein each Ris independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; 'a' is an integer from 0 to 4; and Arand Arare independently at each occurrence an aromatic radical. The purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidines have low color, and are useful for preparing polymers, such as polycarbonates having a low color. The polycarbonates are useful for producing articles.

Methods for purifying 2-aryl-3,3-bis(hydroxyaryl)phthalimidines

Purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidines

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Karnataka, India

Kumar Arun Satyanarayana