| 摘要 |
1300908 Polyhydrazides INVENTA AG 25 Oct 1971 [29 Oct 1970] 49468/71 Heading C3R Polyhydrazides having repeating units of formula where Ar is a divalent aromatic radical, R<SP>1</SP> is hydrogen or an alkyl group and R<SP>2</SP> is an alkyl group, are obtained by condensing (a) an aromatic dicarboxylic acid diester with hydrazine, one of the four hydrogen atoms in the hydrazine optionally being replaced by alkyl, or (b) an aromatic dicarboxylic acid or its dihalide, dinitrile, diamide or di-alkali metal salt with a hydrazine in which one of the four hydrogen atoms or two not attached to the same nitrogen atom are replaced by alkyl, or (c) an aromatic dicarboxylic acid monoester with a hydrazine in which one of the four hydrogen atoms is replaced by alkyl, the condensation being carried out at elevated temperature in chlorosulphonic acid as solvent and condensing agent. Sulphuric acid also may be present and an alkylating agent, e.g. methanol or dimethyl sulphate, is advantageous. In examples dimethyl terephthalate is condensed with dihydrazine sulphate, a mixture of dimethyl terephthalate and dimethyl isophthalate is condensed with dihydrazine sulphate, isophthalic acid is condensed with methyl hydrazine sulphate and disodium benzophenone-4,4<SP>1</SP>-dicarboxylate is condensed with methyl hydrazine sulphate. Uses.-Fibres, films, coatings and moulded articles. |
