5-Isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, polymer with 2,2'-oxybis(ethanol) and 3a,4,7,7a-tetrahydro-1,3-isobenzofurandione 70942-07-3 Diethylene glycol, tetrahydrophthalic anhydride, trimellitic anhydride polymer