Process for isomerizing methyl-delta-4-tetrahydrophthalic anhydride
AssigneeNippon Zeon Co., Ltd.
InventorsMotoyuki Yamato, Tadao Natsuume
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Abstract
A process for isomerizing methyl-delta-4-tetrahydrophthalic anhydride, which comprises heat-treating it at 60.degree. to 300.degree. C. for 0.1 to 30 hours in the presence of at least one nitrogen-containing compound selected from the group consisting of (a) a quaternary ammonium compound and (b) a compound having a nitrogen atom bonded to the carbon atom of the carbonyl group (e.g., an amide, imide, carbamate, urea or semicarbazide compound). The product is liquid at room temperature, and especially suitable for use as a curing agent for epoxy resins.
Claims5
A process for isomerizing methyl-delta-4-tetrahydrophthalic anhydride without double-bond shift, which comprises heat-treating it at a temperature of 60.degree. to 300.degree. C. for a period of 0.1 to 30 hours in the presence of at least one nitrogen-containing compound selected from the group consisting of (a) a quaternary ammonium compound and (b) a compound having a nitrogen atom bonded to the carbon atom of the carbonyl group.
A process for preparing an isomeric mixture of methyl-delta-4-tetrahydrophthalic anhydride which is liquid at 20.degree. C., which comprises isomerizing, without double-bond shift, a material comprising 100 to 20% by weight of 3-methyl-delta-4-tetrahydrophthalic anhydride and 0 to 80% by weight of 4-methyl-delta-4-tetrahydrophthalic anhydride at temperatures of 60.degree. to 300.degree. C. for 0.1 to 30 hours in the presence of at least one nitrogen-containing compound selected from the group consisting of (a) a quaternary ammonium compound and (b) a compound having a nitrogen atom bonded to the carbon atom of the carbonyl group.
Dependencies are inferred from the claim text.