Bayer Aktiengesellschaft

Friedrich Werner

Heinz U Blank

Alfred Mitschker

Harold Heller

Rudolf Braden

Peter M Lange

Heinz Ziemann

Rolf Putter

Axel Ingendoh

Peter P Wenzl

Hans-Karl Soest

Gunter Siegers

Axel Schafer

Herbert V Diehl

Gunther Gramm

According to the process according to the invention for the preparation of anion exchange resins of the poly(meth)acrylamide type by aminolysis of bead polymers of cross-linked poly(meth)acrylic acid esters with excess polyamine, subsequent separation of the anion exchange resins from the liquid phase containing the unreacted polyamine, washing the anion exchangers free of amine with water and recovering the polyamines from the washing waters, the liquid phase containing the unreacted polyamine and the polyamine-containing washing waters are immediately mixed with the bead polymer of cross-linked poly(meth)acrylic acid ester to be subjected to aminolysis, the amount of fresh polyamine necessary for the establishment of the desired polyamine excess is added to the mixture, the mixture thus obtained is distillatively dewatered until its water content has fallen to a value of &lt;7% by weight and the mixture remaining after this distillative dewatering is subjected to aminolysis in the customary manner.

Process for the preparation of anion exchange resins of the

The invention relates to an environment-friendly process for the preparation of weakly acid cation exchange resins by hydrolysis of crosslinked acrylonitrile bead polymers with an alkaline hydrolizing agent at elevated temperature, according to which the bead polymer and alkaline hydrolizing agent are brought together at elevated temperature only.

Process for the preparation of weakly acid cation exchange resins

A process for the preparation of a bifunctional anion exchange resin by partial quaternization of a weakly basic anion exchanger containing tertiary amino groups which process comprises (a) partially loading the weakly basic anion exchanger with a strong acid and (b) quaternizing the partially loaded anion exchanger by means of a customary alkylating agent.

Process for the preparation of bifunctional anion exchange resins, new

An improved process for the preparation of pivaloylpyruyic acid ester by reaction of pinacolin with an oxalic acid dialkyl ester followed by neutralization of the reaction mixture is disclosed, wherein the reactants are mixed at a temperature of -50.degree. to +50.degree. C. and the reaction completed at a temperature of 35.degree. to 200.degree. C.

Process for the preparation of pivaloylpyruvic acid esters

An improved process for the preparation of pivaloylacetic acid esters by decarbonylation of pivaloylpyruvic acid esters at elevated temperatures is described. The process is carried out in the presence of 0.01 to 5 percent by weight of a metal of sub-groups one to eight of the periodic system, which metal is in metallic and/or oxidic form. Initially, 30 percent of the pivaloylpyruvic acid ester to be converted is heated in the presence of the metal, and after conversion of the same there is added additional pivaloylpyruvic acid ester according to the rate at which the pivaloylpyruvic acid ester is converted.

Process for the preparation of pivaloylacetic acid esters

A process for the preparation of neopentylamine which is virtually free from amines with a higher degree of alkylation which comprises contacting neopentanol with ammonia at a temperature of 200.degree. to 300.degree. C. in the presence of a hydrogenation catalyst. The process can be carried out under increased pressure and in the presence of catalytic amounts of hydrogen.

Process for the preparation of neopentylamine

A process for the preparation of hydroxy-diphenylamines by condensation of dihydroxybenzene with an excess amount of primary aromatic amine in the presence of a catalytic amount of an acid at elevated temperature is described wherein the excess aromatic amine and, if appropriate, the reaction product is distilled off from the reaction mixture in the presence of a base.

Process for the preparation of hydroxy-diphenylamines

A process for the preparation of a 2-hydroxycarbazole of the formula ##STR1## wherein R.sup.1 represents hydrogen, halogen or an optionally substituted alkyl, aryl or alkoxy radical Which comprises contacting a diphenylamine of the formula ##STR2## wherein R.sup.1 has the above-described meaning and

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Cologne, Germany

Friedrich Werner