Hoechst Aktiengesellschaft

Wacker-chemie Gmbh

Clariant Corporation

Gunter Roscher

Friedrich Wunder

Hans-Jerg Kleiner

Klaus Eichler

Heinz Schmitz

Peter Wirtz

Horst Langner

Karl-Heinz Schmidt

Ernst I Leupold

Ioan Nicolau

Hans-Joachim Schmidt

Hans Fernholz

Karl-Fred Worner

Dominik Dempf

Bernd Laugwitz

Wolf-Dietmar Kaufmann

Therese Quadflieg

Gunther Heck

Reinhard Gradl

Ludwig Schmidhammer

Rudolf Strasser

Gerhard Dummer

Heinz Litterer

Harald Berger

Wilfried Pressler

Hansjorg Hey

Dirk Bottger

Peter Horstermann

Manfred Schmidt

Carl Christoph Mollenkopf

Rainer Uhmann

Gunter Heck

Klaus H Kaiser

Hermann Neu

Aladar Lienerth

Helmut Schaum

Ernst Selbertinger

Hans-Dietmar Schnabel

Axel Engelmann

Klaus Fichler

Gabriele Ihl

Hermann Leipe

Karl H Schmidt

Erwin Andereya

Rudolf Donth

The present invention relates to a process for preparing vinylphosphonic acids of the formula ##STR1## in which m is an integer from 1 to 20 by heating 2-chloroethylphosphonic acids of the formula ##STR2## in which n is an integer equal to or smaller than m, if desired in the form of a solution, in the absence or presence of a catalyst to a temperature of 180 to 350.degree. C. and eliminating hydrogen chloride and, where appropriate, water under atmospheric pressure or reduced pressure and, if desired, hydrolysing the vinylphosphonic acids of the formula (I).

Process for preparing vinyl-phosphonic acids

Process for the preparation of the non-toxic salts of

Process for preparing alkanephosphonic anhydrides of the formula (I) ##STR1## where R is straight-chain or branched unsubstituted C.sub.1 -C.sub.6 -alkyl and n.gtoreq.3, which comprises pyrolytically eliminating water from an alkanephosphonic acid of the formula (II) or a pyroalkanephosphonic acid of the formula (III) ##STR2## where R is straight-chain or branched C.sub.1 -C.sub.6 -alkyl, without addition of solvent and removing the water from the reaction mixture by means of an inert gas stream.

Process for preparing alkanephosphonic anhydrides

Process for the continuous preparation of dialkyl vinylphosphonates using catalysts at temperatures of from 150.degree. to 270.degree. C. by dissociation of dialkyl acetoxyethanephosphonates at a pressure of from 5 to 500 mbar in contact with a liquid, catalytically active medium while drawing off the dialkyl vinylphosphonates formed and other volatile reaction products as vapors, by conveying the liquid medium in forced circulation via an evaporator while feeding in fresh dialkyl acetoxyethanephosphonate, if desired admixed with catalyst, corresponding to the distillation of dialkyl vinylphosphonates and other volatile compounds, and drawing off non-volatile material formed as byproduct from the liquid circuit to maintain constant conditions.

Process for preparing dialkyl vinylphosphonates

Method of separating vinylphosphonic acid from crude mixtures

Process for the preparation of pure propanephosphonic anhydride, which comprises distilling crude, impure propanephosphonic anhydride having an average degree of polymerization of 20 to 200 and containing less than 0.5% by weight of water by heating to 230 to 300.degree. C. under a pressure of 0.1 to 100 mbar, pure propanephosphonic anhydride having an average degree of polymerization of 20 to 60 being obtained.

Process for the preparation of pure propanephosphonic anhydride

The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO.sub.2 or an iO.sub.2 -Al.sub.2 O.sub.3 mixture with the aid of a binder which comprises

Carrier catalyst, process for its preparation, and its use for the

The invention relates to a method for making a catalyst which contains palladium and/or its compounds and, if desired, additionally gold and/or gold compounds and which contains as activators alkali metal compounds and, if desired, additionally cadmium compounds on a support which is composed of SiO.sub.2 or an SiO.sub.2 -Al.sub.2 O.sub.3 mixture having a surface area of 50-250 m.sup.2 /g and a pore volume of 0.4-1.2 ml/g and whose particles have a particle size of 4 to 9 mm, 5 to 20% of the pore volume of the support being formed of pores having radii of 200 to 3000 .ANG. and 50 to 90% of the pore volume being formed of pores having radii of 70 to 100 .ANG.. The support particles are compressed with the aid of an Li, Mg, Al, Zn or Mn salt of a C.sub.2 -C.sub.20 carboxylic acid or a mixture of such salts as binder.

Method for making a catalyst

Process for the oxidation of dialkyl esters of 2-hydroxy-ethylphosphonic

The invention relates to a process for the isolation of vinyl acetate which involves not combining the bottom product of the recylced gas washings with the water-saturated vinyl acetate but rather introducing it to further multiple distillation columns from the gas mixture formed in the reaction of ethylene with acetic acid and oxygen over catalysts containing palladium or palladium compounds in the gas phase.

Process for the isolation of vinyl acetate by distillation

A process for the preparation of alkyl esters of alkenylphosphinic acid, having the general formula I ##STR1## wherein R.sup.1 represents H or CH.sub.3, R.sup.2 alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 alkyl having from 1 to 8 carbon atoms, which comprises cleaving an alkyl ester of 2-acetoxyethyl phosphinic acid, having the general formula II ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the meaning indicated above, in contact with a liquid catalytically acting medium and at a partial pressure of the total of the components of the reaction system in the range of from 1 to 500 mbar, and drawing off the resulting alkyl esters of alkenyl phosphinic acid and other volatile reaction products. The invention also relates to compounds of the formula I ##STR3## wherein (a) R.sup.1 represents H, R.sup.2 represents alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 represents isobutyl or alkyl having from 5 to 8 carbon atoms, or

Process for the preparation of alkyl alkenylphosphinates

The invention relates to a process for the preparation of vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen-containing gases on a catalyst which contains palladium and/or compounds thereof and if appropriate additionally gold and/or gold compounds and, as activators, alkali metal compounds and if appropriate additionally cadmium compounds, on a support. The support consists of cylindrical particles with curved front faces. The support material is aerogenic SiO.sub.2 or an aerogenic SiO.sub.2 -Al.sub.2 O.sub.3 mixture having a surface area of 50-250 m.sup.2 /g and a pore volume of 0.4-1.2 ml/g, which is formed to the extent of at least 50% by pores having a diameter of 50-200 .ANG..

Process for the preparation of vinyl acetate

A process for the production of dialkyl esters of vinyl phosphonic acid which comprises subjecting dialkyl esters of 2-acetoxyethane phosphonic acid to cleavage by contacting with a liquid catalytically acting medium at a temperature in the range from 150.degree. to 270.degree. C. and under a pressure such that the partial pressures of the total of the components of the reaction system is in the range from 1 to 500 mbar, and drawing off the resulting dialkyl esters of vinyl phosphonic acid and other volatile reaction products.

Process for the preparation of dialkyl vinylphosphonates

The invention relates to a process for the isolation of vinyl acetate from a gas mixture containing vinyl acetate, ethyl acetate, water and carbon dioxide formed in the reaction of ethylene with acetic acid and oxygen in the gas phase over catalysts containing palladium or palladium compounds. The gas mixture leaving the reaction zone is passed into a distillation column and the gas mixture leaving the top thereof is cooled. The gas which is not condensed during the cooling is washed with acetic acid in a washing column, an acetic acid solution containing vinyl acetate being obtained. The bottom product from the distillation column is passed to a second distillation column and a side stream containing ethyl acetate is removed from an enrichment zone above the bottom thereof, all or some of the bottom product from the second distillation column, which product chiefly consists of acetic acid, being used for the wash in the washing column. The top vapor of the second distillation column is cooled. A portion of the organic phase of the condensate thereby formed is passed, together with the acetic acid solution obtained as the bottom product in the washing column, into a third distillation column, which may have an intermediate tray. The bottom product of the third distillation column is passed into a fourth distillation column. Pure vinyl acetate is removed at the top of the fourth distillation column.

Process for the isolation of vinyl acetate

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Kelkheim, Germany

Gunter Roscher