Browse Prior Art Database

Purification of Highly Insoluble Squarylium Dyes

IP.com Disclosure Number: IPCOM000049791D
Original Publication Date: 1982-Jul-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Balanson, RD: AUTHOR [+2]

Abstract

Squarylium dyes can be purified by simply refluxing slurries of the materials for brief time periods in certain high-boiling ether solvents. The process is not a classical recrystallization because the highly insoluble squarylium dyes are only partially dissolved at any one instant of the reflux. However, during the course of the reflux, it is clear that enough squarylium (solid) (see original) squarylium (soln) exchange takes place to clean effectively both the exterior and interior of the squarylium crystals of impurities.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Purification of Highly Insoluble Squarylium Dyes

Squarylium dyes can be purified by simply refluxing slurries of the materials for brief time periods in certain high-boiling ether solvents. The process is not a classical recrystallization because the highly insoluble squarylium dyes are only partially dissolved at any one instant of the reflux. However, during the course of the reflux, it is clear that enough squarylium (solid) (see original) squarylium (soln) exchange takes place to clean effectively both the exterior and interior of the squarylium crystals of impurities.

The solvents which work are mono- and dialkyl ethers of diethylene glycol which boil in the range of 150 degrees to 200 degrees C. Several of the se solvents are marketed under the trade name "CARBITOL" by Union Carbide.

1