| 摘要 |
Acetaldehyde is polymerized at -120 to -20 DEG C. in the presence of a non-basic solid contact catalyst together with a catalyst activator. The solid catalyst may be an inorganic oxide, e.g. aluminium oxide or silica gel or polytrioxane, polyacetaldehyde, polypropylene, polystyrene or an artificial zeolite. The catalyst activator may be a Lewis acid, a complex compound of a Lewis acid or a salt-like compound, e.g. an oxonium or an aryl-diazonium salt, of a Lewis acid. Examples of activators are boron trifluoride, antimony pentachloride, tin tetrachloride, boron trifluoride diethyl etherate, trifluoroacetic acid, ortho-phosphoric acid and the addition compound of boron trifluoride with ortho-phosphoric acid. A solvent e.g. an aliphatic, cycloaliphatic or araliphatic hydrocarbon may be present. |
