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Purification of Pyromellitate Diethyl Ester Diacyl Chloride

IP.com Disclosure Number: IPCOM000037264D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Arnold, AF: AUTHOR [+3]

Abstract

It is proposed to use a hot melt separation technique to purify the chloride intermediate used in the synthesis of polyamic acid ethyl ester (PAETE). The synthesized product is used as a planarizing film in the manufacture of semiconductor chips and its quality level is crucial to the performance of the chip. (Image Omitted)

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Purification of Pyromellitate Diethyl Ester Diacyl Chloride

It is proposed to use a hot melt separation technique to purify the chloride intermediate used in the synthesis of polyamic acid ethyl ester (PAETE). The synthesized product is used as a planarizing film in the manufacture of semiconductor chips and its quality level is crucial to the performance of the chip.

(Image Omitted)

In polyamide syntheses, purity of the components involved reflects directly upon the system properties of the final polymer. In the case of PAETE, the impurities in the starting materials or intermediates may cause premature chain termination which will result in an undesirable, low molecular weight polymer.

In the process steps for PAETE synthesis, shown in the figure, pyromellitate diethyl ester monoacyl chloride is the particularly significant compound containing impurities. This is so whether it is the completely reacted material from Step 2 or as the product of partial hydrolysis of IV or V. In prior art, recrystallization of the chloride from hexane or similar pariffinic solvents was used as a purification step. This approach was difficult to control and resulted in undesirable yields. Manufacturing problems were experienced with the use of low boiling point hexane and in separating a stiff crystalline mass from a small amount of solvent.

In the proposed purification method, the raw material is first collected as a solid by evaporating the solvent and chlorinating compound. Thi...