| 摘要 |
PCT No. PCT/JP90/00351 Sec. 371 Date Nov. 15, 1991 Sec. 102(e) Date Nov. 15, 1991 PCT Filed Mar. 16, 1990 PCT Pub. No. WO91/13929 PCT Pub. Date Sep. 19, 1991.There are disclosed dibenzofuran amorphous polymer comprising a recurring unit represented by following formula (II) and having a molecular weight giving a reduced viscosity of at least 0.2 dl/g as measured in the form of a 0.5% (W/V) solution in N-methyl-pyrrolidone at 25 DEG C., a process for producing said amorphous polymer, a dibenzofuran copolymer comprising, in addition to a recurring unit represented by following formula (II), at least one type of recurring unit represented by following general formula (III) in a specific proportion and having a molecular weight giving a reduced viscosity of at least 0.2 dl/g as measured in the form of a 0.5% (W/V) solution in concentrated sulfuric acid at 25 DEG C., and a process for producing said copolymer. <IMAGE> (II) <IMAGE> (III) wherein A is -O-, -CO-, -S-, -SO2-, a divalent alkylene group or a single bond and n is a number of 0, 1 or 2. There are also disclosed benzofuran derivatives useful as a starting material and a process for producing said derivatives. The above-mentioned amorphous polymer and copolymer are excellent in stability at the time of molding, low in polarity an low in moisture absorption, so that they are useful as starting materials for the manufacture of molded articles.
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