Basf Aktiengesellschaft

Jaroslav Melzer

Wolfram Bergold

Friedrich Linhart

Hans-Juergen Degen

Hans-Uwe Schenck

Hubert Meixner

Otto Hertel

Emil Scharf

Max Appl

Ralf Hemel

Siegfried Schreiner

Arnold De Clercq

Wilhelm Goesele

Gert Treiber

Werner Schuster

Gunter Niesar

Manfred Jaensch

Norbert Benninghoff

Paper, board and cardboard are produced from paper stocks which contain tacky impurities by the addition of surfactants and cationic polymers having a charge density of at least 1.5 meq/g (measured at pH 7) and a molar mass M,of the cationic polymers of at least 15,000 and drainage of the paper stocks with fixation of the tacky impurities in the paper produced.

Method for producing paper, pulpboard and cardboard

In antifoams based on oil-in-water emulsions, the oil phase of the emulsions contains

Antifoam based on oil-in-water emulsion

The measuring arrangement consists of successive workstations which comprise a stock of paper samples, a balance, a mechanized moistening means for the sample and a blotting means, likewise mechanized, for the moistened sample. An industrial robot controllable by a program and equipped with a gripping apparatus is provided for carrying out the measurement. This arrangement determines the liquid absorbed by paper using the Cobb method and permits the measuring method to be carried out in a fully mechanized manner.

Measuring arrangement for determining the liquid absorption of paper

Individual air permeably sheetlike structures are efficiently lifted from a pile by a vacuum lifter and deposited again at a processing station, the pile including as an alternate interlayer a sheet of air impermeable material.

Separating sheetlike structures from piles

The maximum amounts of the retention-influencing variable stock components which can be added are determined as a function of a predetermined degree of flocculation and typical values of the stock suspension with the aid of a mathematical relationship, and control signals for metering retention aids are derived from the amounts so that the greatest possible retention can be achieved without exceeding a set-point for the degree of flocculation.

Process for controlling the addition of retention aids in papermaking

Stabilized water-containing sodium dithionite formulations which have been rendered alkaline have the consistency of a pumpable paste. They additionally contain readily soluble sodium salts and/or potassium salts which are inert to sodium dithionite and whose water-solubility at 20.degree. C. exceeds 500 g/l. These salts are present in the aqueous phase in an amount of not less than 200 g/l. The pastes are useful reducing agents.

Stabilized water-containing sodium dithionite formulations which have

In antifoams based on oil-in-water emulsions, the oil phase of the emulsion contains

Antifoams based on oil-in-water emulsions

A process for the preparation of water-soluble polymeric crosslinking agents by a two-stage reaction of di-secondary diamines with epichlorohydrin and/or dichlorohydrin, wherein, in the first stage, di-secondary diamines are condensed with epichlorohydrin and/or dichlorohydrin in a molar ratio of from 1:0.5 to 1:1 at a pH of from 9 to 12, and in the second stage the condensates obtained in the first stage are reacted with additional epichlorohydrin and/or dichlorohydrin at a pH of from 4 to 8.5. The water-soluble condensates thus obtained are crosslinking agents for polyamines, polyamidoamines, ethyleneimine-modified polyamidoamines and polyether-amines. The crosslinking reaction gives water-soluble condensates, which possess a high cation activity and may be used as retention aids, drainage aids and flocculants in the manufacture of paper.

Preparation of water-soluble condensates and their use as crosslinking

Mixtures of high molecular weight polyacrylamides in the form of a water-in-oil polymer dispersion and containing in the inner phase from 99.99 to 95% w/w of a cationic polyacrylamide and from 0.01 to 5% w/w of an anionic polyacrylamide or from 99.99 to 95% w/w of an anionic polyacrylamide and from 0.01 to 5% w/w of a cationic polyacrylamide, all percentages being based on the total amount of polymer. The said polymer mixtures are particularly effective retention aids and flocculants and are preferably used in the manufacture of paper as pulp additives.

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Ludwigshafen, Germany

Jaroslav Melzer