| 摘要 |
1,249,708. Oxymethylene copolymers. CELANESE CORP. 12 Feb., 1969 [12 Feb., 1968], No. 7492/69. Heading C3P. An oxymethylene copolymer is prepared by subjecting trioxane to liquid phase polymerization with one or more comonomers in the presence of a chain transfer agent and, as catalyst, a salt or acid having a hexachloroarsenate, hexafluoroarsenate, hexachlorophosphate or hexafluorophosphate anion, the salt or acid being stable and soluble in at least one of the monomers used. Suitable chain transfer agents are C 1-18 alcohols, C 1-18 carboxylic acids or anhydrides, polyoxymethylene dialkyl ethers, polyoxymethylene diesters, and the reaction products of C 1-18 primary or secondary alcohols and C 1-7 aldehydes. Suitable catalysts are aryl diazonium, aryl oxonium and alkyl oxonium salts. In the example trioxane and ethylene oxide are copolymerized in the presence of methylol, p-chlorophenyldiazonium hexafluorophosphate and methylene chloride. The polymer is hydrolysed with tri-n-butylamine in methanol/water to give stable hydroxy ethyl ether end groups. |
