Hoechst Aktiengesellschaft

Kasimir Ruchlak

Christoph Heinze

Rolf Kranzle

Karl-Heinz Reichert

Walter Fester

Heinz Muller

Helmut Kraus

Ernst-August Albers

Horst Wolff

Hans Huber

Heiner Zimmermann

Hermann Scheibler

Holm Steude

Wolf-Dieter Mitterberger

Pulverulent polyvinyl chloride molding compositions capable of being sintered are produced by polymerizing vinyl chloride in suspension using suspension stabilizers and non ionic wetting agents and as emulsifier alkylaryl- and/or alkyl sulfonic acids. The molding compositions are especially suitable for making separating plates for electric cells.

Polyvinyl chloride molding compositions and process for making same

Powdery molding compositions capable of being sintered made from polyvinyl chloride, which are especially suitable for the manufacture of separator plates for electric cells, and which substantially consist of a suspension polyvinyl chloride, from 0.003 to 0.45 weight %, relative to the molding composition, of free sulfonic acids selected from the group of alkylarylsulfonic acids and/or alkylsulfonic acids, and 1/9 to 7/3 of said 0.003 to 0.45 weight % of anions of said sulfonic acids, in the form of their salts with organic cations, selected from the group of quaternary ammonium cations.

Finely distributed polyvinyl chloride molding compositions capable of

.alpha.-Ethylenically unsaturated monomers are polymerized in aqueous media in a vessel with electrically conductive inner surface, in which partial areas of the inner surface covered by liquid are electrically insulated from the remaining surface areas and conductively connected therewith by an external source of current. In this manner the formation of deposits on the wall of vessel is hindered or suppressed.

Process and apparatus for polymerizing .alpha.-ethylenically unsaturated

The present invention is related to the process of concentrating K-polymer-latices by ultra filtration carried out by means of a semi-permeable membrane made of a synthetic polymer having a determined molecular weight, comprising that the membrane is pretreated with an emulsifier solution prior to ultra filtration. This operation substantially prevents the formation of solid matter deposits on the membrane.

Process for concentrating latices

The present invention relates to a vessel and a process for polymerizing vinyl chloride in suspension. The vessel the inner surfaces of which consist of stainless steel or are plated with a noble metal comprises at least one cathode in contact with the reaction medium and insoluble therein and as anode the metallic inner surface of the vessel, the cathode and anode being connected over an external source of current. The polymerization is carried out with electrolytic generation of hydrogen and oxygen from the polymerization medium. The polymerization vessel and process according to the invention suppress completely or substantially the formation of wall deposits.

Polymerization process

Pulverulent polyvinyl chloride molding compositions capable of being sintered are produced using as emulsifier an alkyl-aryl or alkyl-sulfonic acid or a mixture thereof. Prior to or during polymerization 20 to 80 % of the emulsifier are added, optionally together with other auxiliaries, and the balance is applied to the separated polymer. The molding compositions are especially suitable for the manufacture of separating plates for electric cells.

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Burgkirchen, Alz, Germany

Kasimir Ruchlak