Verfahren zur Herstellung von Polyoxymethylen

摘要

Trioxane is polymerized using as catalyst one or more compounds of formula where X is R1 or R2O, Y is -OR3 or when X is R1 or -OR3 or -OR5 or halogen when X is R2O, with R4 being an aryl group which may have functional substituents, R1 being the same as R4 when Y is and an aryl or substituted aryl group is excluded from R2 when Y is halogen, or of formula where X is R1-, R1O-, R1NH- or R1R2N-, Y is R3O, R3S, or and R1, R2, R3 and R5 may be the sam or different and represent alkyl, aryl, cycloalkyl, aralkyl, or alkenyl groups which may have functional substituents and X and Y may also form a ring. The catalyst may be a salt of sulphurous acid, sulphuric acid containing organic substituents such as alkyl, aryl or aralkyl groups, pyrosulphuric acid, thiosulphuric acid, thiosulphuric acid containing organic substituents such as alkyl, aryl or aralkyl groups, polythionic acid or acid salts of sulphuric acid, e.g. m-nitrobenzene sulphonic acid ethyl ester, diethyl sulphurous acid, sodium lauryl sulphate, dipotassium pyrosulphate, the anhydride of m-nitrobenzene sulphonic acid, and the mixed anhydride of m-nitrobenzene-sulphonic acid and acetic acid amongst others. The polymerization may take place by bulk, dispersion-solvent techniques.