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US 3,972,902 AGranted
4,4'-Isopropylidene-bis(3- and 4-phenyleneoxyphthalic anhydride)
AssigneeGeneral Electric Company
InventorsDarrell R. Heath, Joseph G. Wirth
Life of this patent
Estimating the term…
Abstract
Aryloxy dianhydrides are prepared from the hydrolysis of the reaction product of a nitro-substituted phenyl dinitrile with a metal salt of a dihydroxy aryl compound in the presence of a dipolar aprotic solvent.
Claims2
The compound 2,2-bis-[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride.
The compound 2,2-bis-[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride.
Dependencies are inferred from the claim text.