Reaction mixtures, processes for their preparation and their use as polymerization initiators
AssigneeBayer Aktiengesellschaft
InventorsHeinrich Wolfers, Hans Rudolph, Hans J. Rosenkranz
Life of this patent
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Abstract
Mixtures obtained by reaction of an .alpha.-arylketone or of an arylaldehyde and the equivalent amount of a base metal in an inert aprotic solvent with a di-, tri- or tetrachlorosilane or a chlorinated polyorganosilane or -siloxane work as initiators for free radical-initiated polymerization reactions.
Claims3
A process for the preparation of a reaction mixture suitable as an initiator for free radical-initiated polymerisation reactions, which comprises reacting 1 mol of an .alpha.-arylketone or of an arylaldehyde of the general formula V or VI respectively ##STR11## wherein R.sup.4 represents an aryl radical optionally substituted by C.sub.1 -C.sub.4 alkyl, methoxy, chlorine or fluorine, and R.sub.6 represents an aryl radical optionally substituted by C.sub.1 -C.sub.4 alkyl, methoxy, chlorine or fluorine, or a C.sub.1 -C.sub.6 -alkyl radical optionally substituted by C.sub.1 -C.sub.4 alkyl, methoxy, chlorine or fluorine, or a C.sub.5 -C.sub.7 -cycloalkyl radical or hydrogen, and approximately the equivalent amount of a base metal in an inert aprotic solvent at -10 to +70.degree. C. with 0.4 to 0.8 mol of a dichloro-organosilane of the general formula VII
- r.sup.1 r.sup.2' siCl.sub.2 (VII)
- or with 0.25 to 0.6 mol of a trichloro-organosilane of the general formula VIII
- r.sup.1 siCl.sub.3 (VIII)
- wherein R.sup.1 represents a methyl, ethyl, phenyl, benzyl or chloromethyl radical, and R.sup.2 represents a chlorine atom, a hydroxyl, methoxy, or ethoxy radical, or one of the substituents R.sup.1 or with 0.1 to 0.7 mol of tetrachlorosilane, chlorinated polyorganosilanes or -siloxanes having a molecular weight of 150 to 3.000 until the exothermic reaction has ended, hydrolysing the reaction product, separating off the organic phase and stripping off the solvent under a pressure of between 2 and 6 mm Hg.
Oligomeric silyl ethers with a molecular weight, determined as a number-average, of 500 to 5,000 of the general formula I ##STR12## wherein R.sup.1 denotes a methyl, ethyl, phenyl, benzyl or chloromethyl radical,
- R.sup.2 denotes a chlorine atom, a hydroxyl, methoxy or ethoxy radical, R.sup.1 or A,
- R.sup.3 denotes a chlorine atom, a hydroxyl radical or A,
- R.sup.4 and R.sup.5 each denote an aryl radical optionally substituted by C.sub.1 -C.sub.4 -alkyl, methoxy, chlorine or fluorine,
- R.sup.6 and R.sup.7 each denote either R.sup.4 or R.sup.5 or an alkyl radical with 1-6 C-atoms which is optionally substituted by C.sub.1 -C.sub.4 -alkyl, methoxy, chlorine or fluorine, or a cycloalkyl radical with 5-7 C. atoms or hydrogen,
- R.sup.8 denotes hydrogen or a silyl radical of the general formula II ##STR13## and a denotes a radical of the general formula III ##STR14## the compounds of the general formula I containing one to twenty partial structures IV ##STR15##
Dependencies are inferred from the claim text.