Bayer Aktiengesellschaft

Other

Kemira Oyj

Heinz Giesecke

Bernd Hauschel

Bernhard Hunke

Roderich Raue

Alfred Brack

Peter-Roger Nyssen

Dirk Pf&uuml;tzenreuter

Karl-Heinz Drenker

Reiner Gottschalk

Claudia Hundertmark

A process for whitening paper in a size press includes contacting a cellulose sheet with a size press liquor that contains a surface size and a particular whitener containing sulfonate groups and cations, M, wherein at least 10% of all cations M have the formula in which Rto R, independently of one another, denote hydrogen, a C-C-alkyl radical or an optionally further substituted C-C-hydroxyalkyl radical, and Rdenotes an optionally further substituted C-C-hydroxyalkyl radical. The process provides superior paper whitening compared to a corresponding process in which the whitener cations are all sodium or potassium ions.

Alkanolammonium-containing triazinyl flavonate whiteners

The use of optical brighteners of the formula (II): in which and the other substituents have the meaning stated in the description, for brightening aqueous coating slips comprising at least one latex binder and at least one synthetic co-binder differing therefrom.

Use of brighteners for the preparation of coating slips

Preparations of solids containing graft copolymers

Dyestuffs of the general formula ##STR1## wherein R.sub.1 denotes alkyl, alkenyl, aralkyl or cycloalkyl,

Process for the preparation of cationic hydrazone dyestuffs

To prepare dyestuffs of the general formula ##STR1## in which R.sup.1 and R.sup.2 represent methyl or ethyl,

Process for the preparation of cationic dyestuffs

Pyridine-4-aldehyde phenylhydrazones are prepared by catalytic hydrogenation of 4-cyano-pyridine under normal pressure or almost normal pressure in the presence of phenylhydrazine or nuclear-substitution products thereof, in an aqueous medium in the absence of organic solvents, at a pH value between 9 and 12, preferably between 9.5 and 11, and in a temperature range from 0.degree. to 60.degree. C.

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Leverkusen, Germany

Heinz Giesecke