abstract |
Fiber-forming aromatic polyester consisting essentially of 1,4-dioxyphenylene units, lower alkyl or halo-1,4-dioxyphenylene units, terephthaloyl units and 3-carbonyl-4'-oxybenzophenone or 4-carbonyl-4'-oxybenzophenone units or chloro- and/or methyl substituted homologs of these. |