Basf Aktiengesellschaft

Universitaet Bruanschweig

Michael Kroener

Heinrich Hartmann

Walter Denzinger

Friedrich Linhart

Andreas Stange

Norbert Sendhoff

Claudia Nilz

Fritz Brunnmueller

Rolf Fikentscher

Sigberg Pfohl

Enrique Freudenberg

Hans-Juergen Degen

Werner Auhorn

Wolfgang Hoelderich

Rolf Schneider

Dietmar Moench

Volkmar Weberndoerfer

Werner Biffar

Klaus Flory

Hans Mueller

Alfred Oftring

Hardo Siegel

Gerd Rehmer

Matthias Irgang

Wolf D Mross

Wilfried Heide

Jacques Dupuis

Primoz Lorencak

Horst Neuhauser

Rudi Widder

Wolfgang Kowalsky

Rudolf Schuhmacher

Ulrich Koehler

Hans-Hermann Johannes

Theo Proll

Rainer Tresch

Willi Schmidt

Karl-Heinz Beyer

Lutz End

Thomas-Michael Kahl

Eberhard Ambach

Peter Kroetzsch

Friedrich Brunnmueller

Walter Goetze

Hans Burkert

Karlheinz Stecher

Sven Ammermann

Ute Jana Weinaug

Werner Schoch

The present invention relates to light emitting compounds, especially to triplett emitters suitable for electrooptical applications. Compounds according to the invention are organometallic complexes of a metal, preferably Ir, having a backbone of one five-membered ring that is linked to a five- or six-membered ring, by an intermediate six-membered ring. These compounds are suitable for adaptation to the emission of light in the UV to NIR range by adaptation of atoms or groups within at least one of the five-membered or six-membered ring structures.

Triplet emitter having condensed five-membered rings

Elimination of nitrile impurities from polymers

Copolymers which are obtained by copolymerization of a) from 5 to 99 mol % of N-vinylcarboxamides, b) from 95 to 1 mol % of monoethylenically unsaturated carboxylic acids and/or the alkali metal, alkaline earth metal, ammonium or amine salts thereof, and if required, c) up to 30 mol % of other monoethylenically unsaturated compounds, and if required, d) up to 2 mol % of crosslinking agents, and subsequent partial or complete elimination of the acyl groups from the N-vinylcarboxamides polymerized in the copolymer, with formation of amino or ammonium groups, are used as additives to paper stock for increasing the drainage rate and the retention in papermaking, and the dry and wet strength of the paper.

Use of hydrolyzed copolymers of N-vinylcarboxamides and

Insoluble, only slightly swellable polymers containing amino groups,

Graft polymers are obtainable by free radical polymerization of

Graft polymers of natural substances containing saccharide structures or

Catonic urea/formaldehyde resins, their preparation and their use in the

Cationic urea/formaldehyde resins are obtainable by condensing urea and formaldehyde in a molar ratio of from 1:1.5 to 1:3 in the presence of polymers which contain not less than 1 mol % of polymerized vinylamine units and have Fikentscher K values of from 5 to 300, in an amount of from 5 to 50 g per mole of urea in the end product, where the mixture is first a) precondensed at a pH of from 8 to 14, then acidified and b) condensed at a pH of from 1 to 5 until gel formation begins, c) then from 0.3 to 1.5 moles of formaldehyde are added per mole of urea used, d) post-condensation is carried out and e) the resin solution is subsequently neutralized. The resins thus obtained are used in papermaking as assistants for increasing the dry and wet strength of paper and result in less dulling of the whiteness of the paper.

Cationic urea/formaldehyde resins, their preparation and their use in

A process for the preparation of 4-substituted imidazoles of the general formula ##STR1## in which R denotes C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, aryl, and C.sub.7 -C.sub.20 aralkyl, wherein

Preparation of 4-substituted imidazoles from

A method of stabilizing N-vinylformamide, which may contain customary polymerization inhibitors, against polymerization during storage or transport, comprises adding to the N-vinylformamide monomers of the general formula ##STR1## where R+H, CH.sub.3 ##STR2## R.sup.2 +C.sub.1 -C.sub.4 -alkyl, as stabilizer in amounts of from 1 to 99 .degree.6 by weight, based on the mixture.

Stabilization of monomeric N-vinylformamide

N-vinylformamide is polymerized with or without other water-soluble monoethylenically unsaturated monomers and with or without water-insoluble monoethylenically unsaturated monomers in not less than 30% strength by weight aqueous monomer solutions in the presence of a polymerization initiator at not more than 150.degree. C. in a kneader by a method in which the polymerization is carried out to such an extent that the initially formed water-containing polymer gel disintegrates into fine particles and the finely divided polymer obtainable in this manner is hydrolyzed, preferably in the kneader, so that not less than 0.1 mol % of the N-vinylformamide units present in the polymer are converted into vinylamine units. The polymers obtainable in this manner dissolve readily in water. The aqueous solutions are used, for example, in papermaking and tertiary oil production.

Preparation of finely divided, water-soluble polymers containing

Poly-N-vinylformamide which contains structural units of the formula ##STR1## and a terminal double bond of the formula ##STR2## is prepared by anionic polymerization of N-vinylformamide in the presence of bases.

Anionically polymerized N-vinylformamide and the preparation thereof

Paper, board and cardboard are produced by draining a paper stock, containing undesirable substances, in the presence of hydrolyzed homo- and/or copolymers of N-vinylformamide having a degree of hydrolysis of not less than 60% and a cationic retention aid. According to the invention, faster drainage and improved retention are obtained compared with the use of known fixing agents.

Production of paper, board and cardboard

Stable water-in-oil emulsions of a hydrolyzed polymer of an N-vinylamide of the formula ##STR1## where R and R.sup.1 are each H or C.sub.1 -C.sub.6 -alkyl, are prepared by polymerizing a compound of the formula I, alone or as a mixture with other monoethylenically unsaturated monomers, in the form of a water-in-oil emulsion to give a water-in-oil polymer emulsion, and then hydrolyzing the polymer, hydrolysis of the polymer in the form of the water-in-oil polymer emulsion being carried out in the presence of an acid or base, and additives in the form of antioxidants, reducing agents or aldehyde acceptors being added for stabilization.

Preparation of stable water-in-oil emulsions of hydrolyzed polymers of

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Mannheim, Germany

Michael Kroener