Method for producing decolored polyester, decolored polyester, and decoloring agent
AssigneesShintech Corporation, Jeplan, Inc.
InventorsMasaki TAKAO, Toru SAKAI, Hiroshi FUJITA, Shuji INADA
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Abstract
A method for producing a decolorized polyester according to the present invention includes: a step of preparing a polyester colored with a colorant, and a decolorizing agent containing a glycol ether-type compound having a boiling point at atmospheric pressure of 160° C. or higher; and a step of removing the colorant, by bringing the decolorizing agent into contact at least once with the colored polyester while heating the decolorizing agent to a temperature equal to or lower than a melting point of the polyester, to thereby obtain the decolorized polyester.
Claims2
A decolorized polyester obtained by removing a colorant having a chromophore containing nitrogen atoms from a polyester colored with the colorant,
- wherein an amount of the nitrogen atoms contained in the decolorized polyester is 30 ppm or less.
A decolorizing agent used for decolorizing a polyester colored with a colorant by removing the colorant therefrom,
- wherein the decolorizing agent contains a glycol ether-type compound having a boiling point at atmospheric pressure of 160° C. or higher.
Dependencies are inferred from the claim text.