Silyl ethers and their use as polymerization initiators

Silyl ethers of the formula ##STR18## in which A, B and D represent aryl radicals with 6-12 C atoms which are optionally substituted by methyl, methoxy or chlorine,

• R.sup.1 represents hydrogen, an alkyl radical with 1-18 C atoms, a cycloalkyl radical with 5-7 C atoms, an aralkyl radical with 6-8 C atoms or a phenyl, naphthyl or biphenyl radical which is optionally substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, or chlorine,
• R.sup.2 represents alkyl radicals with 1-6 C atoms, cycloalkyl radicals with 5-7 C atoms, aralkyl radicals with 6-8 C atoms and a phenyl radical which is optionally substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, or chlorine, R.sup.3 represents a n-alkyl radical with 1-6 C atoms or a phenyl radical and
• n represents 0 or 1 (but in the case where R.sub.1 denotes hydrogen, represents only 0).