Patent ID: 7557243

Claim:
A terephthalic acid composition comprising: (1) terephthalic acid in an amount greater than 50 percent by weight; (2) (a) 4-carboxybenzaldehyde in an amount ranging from 1 ppm to 1000 ppm; or (b) p-toluic acid in an amount ranging from 1 ppm to 1000 ppm; or both (2) (a) and (2) (b); and (3) at least two of the following: (a) isophthalic acid in an amount ranging from 50 ppm to 49 wt %; (b) trimellitic acid in an amount ranging from 140 ppm to 1000 ppm; (c) 4,4′-dicarboxybiphenyl in an amount ranging from 25 ppm to 49 wt %; (d) phthalic acid in an amount ranging from 20 ppm to 49 wt %; (e) 4-hydroxybenzoic acid in an amount ranging from 3 ppm to 1000 ppm; (f) 4-hydroxymethylbenzoic acid in an amount ranging from 40 ppm to 49 wt %; and (4) benzoic acid in an amount ranging from 1 ppm to 3000 ppm.