Purification process for hydrolysable organic solvent

Patent metadata

Field	Value
Publication number	US-10913058-B2
Application number	US-201616067041-A
Country	US
Kind code	B2
Filing date	Dec 16, 2016
Priority date	Dec 28, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

Methods for the removal of ionic contaminants from hydrolysable organic solvent by ion exchange resins are described. A mixed bed of ion exchange resin with cationic ion exchange resin and weak-base anionic ion exchange resin is used in such methods.

First claim

The invention claimed is:

1. A method for removing ionic contaminants from a hydrolysable organic solvent selected from the group consisting of an ester, an amide, a carbonate, and mixtures thereof, the method comprising contacting the hydrolysable organic solvent with a mixed bed of ion exchange resin comprising cationic ion exchange resins and anionic ion exchange resins, wherein the anionic ion exchange resins are selected from weak-base anionic ion exchange resins, wherein the contents of Na, K, Ca, Al, Fe, Ni, Zn, Cu, Cr and Sn in the cationic ion exchange resins and the anionic ion exchange resins are 5 ppm or less based on the dry-weight of the cationic ion exchange resins and anionic ion exchange resins, and wherein following contact with the mixed bed of ion exchange resin, the hydrolysable organic solvent comprises 0.1 ppb or less of each of Na, K, Ca, Al, Fe, Ni, Zn, Cu, Sn and Cr.

2. The method of claim 1 , wherein the weak-base anionic ion exchange resins have tertiary amine groups.

3. The method of claim 1 , wherein the content of water in the cationic ion exchange resins and the anionic ion exchange resins are 5 weight % or less respectively.

4. The method of claim 1 , the mixed bed of ion exchange resin comprises 10 ppb or less of leachable species of low-molecular organic compound measured by the following method:
washing the ion exchange resin by 50 BV/Hr of ultra pure water flow for 2 hours, analyzing total organic carbon values of water before and after contacting with the washed ion exchange resin, then calculating the difference of the total organic carbon values of the water by subtracting the total organic carbon value of water after contacting with the ion exchange resin from the total organic carbon value of water before contacting with the ion exchange resin.

5. The method of claim 1 , wherein the hydrolysable organic solvent is a compound having an ester bond.

Assignees

• Dow Global Technologies Llc

Inventors

• Ohba Kaoru
• Takano Kenji
• Iida Masonori
• Abe Shinnosuke
• Masudo Takashi
• Kishizaki Osamu
• Ishibashi Ryo
• Yamashita Yusuke

Classifications

• B01D15/00

  Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor · CPC title

• B01J41/12

  Macromolecular compounds · CPC title

• B01D15/363

  Anion-exchange · CPC title

• B01J41/07

  in the weakly basic form · CPC title

• B01J47/04 Primary

  Mixed-bed processes · CPC title