Merck Patent Gesellschaft MIT Beschrankter Haftung

Merck Patent Gesellschaft MIT Beschraenkter Haftung

Claus P Herz

Karl-Heinz Neisius

Jurgen Eichler

Dieter Dorsch

Rudolf Eidenschink

Gregor Wehner

Eike Poetsch

Michael Romer

Manfred Kohler

Jorg Ohngemach

Otto Stahlecker

Klaus Praefcke

Bernd Kohne

Jurgen Gehlhaus

J/u/ Rgen Eichler

Vertically oriented polymer materials with nonlinear optical properties are obtained by polymerization of monomers containing polar groups.

Oriented polymer materials

Articles having a substrate coated with a oriented polymer having polar monomer units wherein the monomer units and main polymer chains originate from cyclic monomers polymerized by ring opening polymerization through impinging light on the coated surface.

Ketones of the formula II ##STR1## with Ar, R.sup.1 and R.sup.2 as indicated below, can be hydroxylated, readily and in high yields, in the .alpha.-position using tetrahalogenomethanes and alkali metal hydroxides under phase-transfer conditions.

Process for the preparation of ketones

Polymer compositions exhibiting liquid-crystalline phases contain chemically bonded mesogenic groups of the formula Ia and/or Ib: ##STR1## in which Q.sup.1 is H, alkyl or alkoxy having 1-5 C atoms, F, Cl, Br or CN,

Polymer compositions exhibiting liquid-crystalline phases

Hydroxyalkylphenones of formula I ##STR1## wherein R is hydrogen, halogen, alkyl of 1 to 18 C atoms, alkoxy of 1 to 4 C atoms or ##STR2## R.sub.a is hydrogen, halogen or alkyl of 1 to 4 C atoms; R.sup.1 and R.sup.2 (a) are each alkyl of up to 14, together 4 to 16, C atoms or together are alkylene of 4 to 8 C atoms, if R is hydrogen, halogen, alkyl of 1 to 6 C atoms or alkoxy of 1 to 4 C atoms, or (b) are each alkyl of 1 to 6 C atoms or together are alkylene of 2 to 8 C atoms, if R is alkyl of 3 to 18 C atoms or ##STR3## R.sup.3 and R.sup.4 are each alkyl of 1 to 6 C atoms or together are alkylene of 2 to 8 C atoms and Z is --CO--, --CH.sub.2 --, --O-- or --S--; are suitable as initiators for radiation curing aqueous prepolymer dispersions. They have good stability in aqueous systems and also upon removal of the water from these systems, and they have a considerably increased reactivity in their ability to initiate the curing of aqueous systems curable by radiation.

Use of hydroxyalkylphenones as initiators for radiation curing of

Compounds of the formula ##STR1## wherein A, X, Z, R.sup.1, R.sup.2, R.sup.3, R.sup.4, n and m are defined hereinbelow are effective photoinitiators especially for the photopolymerization of ethylenically unsaturated compounds and for the curing of printing inks.

Aromatic-aliphatic ketones useful as photoinitiators

The stereospecific preparation of D(+)-biotin is improved by a synthetic route involving the conversion of 3,4-isopropylidene-D-arabinose in which the OH group in the 2-position is not protected, into an ester of 6,9-dihydroxy-7,8-isopropylidenedioxynona-2,4-dienoic acid, the latter then being catalytically hydrogenated and subsequently converted into D(+)-biotin in a manner known per se.

Process for the preparation of D(+)-biotin

Mixtures containing at least one hydroxyalkylphenone of the formula ##STR1## wherein R.sup.1 is H, alkyl of 1-4 C atoms or chlorine, R.sup.2 is H or methyl, R.sup.3 is H or methyl, R.sup.4 is alkyl of 1-6 C atoms and R.sup.5 is alkyl of 1-6 C atoms, and at least one 2-alkylthioxanthone of the formula ##STR2## wherein R.sup.6 is alkyl of 1-8 C atoms, have a considerably increased reactivity in initiating the photopolymerization of ethylenically unsaturated compounds. The polymers fully hardened using these initiator mixtures suffer only little yellowing.

Mixtures of aromatic-aliphatic ketones as photoinitiators and

Compounds of the formula ##STR1## wherein the substituents A, Z, R.sup.1, R.sup.2, R.sup.3, R.sup.4, X, n and m are defined hereinbelow

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Heidelberg, Germany

Claus P Herz