| 摘要 |
<p>Title dianhydride of formula (I) - is a crystalline, colourless, extremely thermostable cpd. which can be used as a chemical inter., partic. as a monomer in the prodn. of e.g., polyesters and polyamides with high thermal stability and good affinity for dyes. (I) is prepd. by dehydration of 3,31-disulpho-diphenyl sulphone 4,41-dicarboxylic acid (prepd. by condensing toluene with H2SO4, sulphonating the resulting 4,41-dimethyldiphenyl sulphone, and oxidising the resulting 4,41-dimethyl-3,3'-disulpho-diphenyl sulphone), e.g. by treating with a carbodiimide, acetyl chloride or acetic anhydride in the presence or absence of a solvent.</p> |
