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Purification of 4, 4' Diaminophenyl Ether

IP.com Disclosure Number: IPCOM000038186D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Arnold, AF: AUTHOR

Abstract

A special recrystallization process has been proposed to purify 4, 4' diaminophenyl ether (DAPE), commonly known as oxydianiline (ODA), prior to its being used to manufacture polyamic acid ethyl ester (PAETE). The method is simple, economical and effective in providing a high quality material free of oxidation products.

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Purification of 4, 4' Diaminophenyl Ether

A special recrystallization process has been proposed to purify 4, 4' diaminophenyl ether (DAPE), commonly known as oxydianiline (ODA), prior to its being used to manufacture polyamic acid ethyl ester (PAETE). The method is simple, economical and effective in providing a high quality material free of oxidation products.

DAPE is the standard building block in making polyimide precursor polymers, such as PAETE, for use in the manufacture of semiconductor devices. The diaminophenyl ether is quite susceptible to oxidation, especially in the presence of moisture. It is highly desirable to purify the compound prior to polymerization. Previous methods used for purification included zone recrystallization, sublimation, or repeated water/methanol washes. The methods have a tendency to be expensive or time-consuming, are not readily adaptable to manufacturing operations, or are inefficient.

The disclosed process answers the foregoing concerns by being inexpensive and readily manufacturable with a minimal handling of the compound. The solid DAPE is dissolved in an HCl solution to a pH of 3.3. A carbon adsorbent is added and after a suitable time the solution is filtered. Under ideal conditions, the liquor is colorless. However, if a trace of the red color existant when the DAPE is initially dissolved is present, the steps may be repeated.

An ammonia solution added to the liquor causes a fine white precipitate to be formed which is f...