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Chlorodiane Blue Recrystallization

IP.com Disclosure Number: IPCOM000083970D
Original Publication Date: 1975-Aug-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hunziker, HE: AUTHOR [+2]

Abstract

Chlorodiane blue (CDB), 3,3'-dichloro-4,4'-diphenyl bis-(1"-azo-2"-hydroxy-3"naptha , has been found to be soluble in liquid ammonia at -78 degrees C or at the boiling point of liquid ammonia.

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Chlorodiane Blue Recrystallization

Chlorodiane blue (CDB), 3,3'-dichloro-4,4'-diphenyl bis-(1"-azo-2"-hydroxy- 3"naptha , has been found to be soluble in liquid ammonia at -78 degrees C or at the boiling point of liquid ammonia.

For purification, CDB (200 mg.) is dissolved in liquid ammonia (0.2 1) at -78 degrees C which has been distilled from the storage cylinder. This and all processes are done with the exclusion of light, water, and air. A cosolvent, here, tetrahydrofuran (200 ml) (Fisher anhydrous, containing 0.025% butylated toluene) is slowly added. The solution is allowed to warm, and solvent (NH(3)) allowed to evaporate. Filtration of the resulting suspension gives C~B pigment and a filtrate containing red impurities.

The resulting pigment was examined in two ways. Scanning electron microscopy (x3SK) shows structure in the particles, with the appearance of sheets about 0.1 Mu thick. The material before treatment shows little or no structure. The electrophotographic properties of the pigment were found to have been improved by the process.

Various amines may also be used to recrystallize chlorodiane blue, in place of the liquid ammonia.

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