Bayer Aktiengesellschaft

Adolf Wissner

Gerd-Michael Petruck

Raimund Wambach

Werner Hauser

Udo Birkenstock

Josef Haydn

Sigurd Hartung

Paul R Wambach, Deceased

Feliks Bitners

Alexander Mitrowsky

In the new shaped articles a hollow space or a lumpy inorganic base material is surrounded by a porous silica-containing layer. They can be prepared by applying silica sol or a mixture containing water, silica sol and/or waterglass and, if appropriate, finely pulverulent water-insoluble silica and/or porosity producing agents to a lumpy base material, and, if use is made of organic base materials, then removing these organic base materials by heating. The new shaped articles can be used as support material for catalysts or, if the layer containing the porous silica contains catalytically active substances, as catalysts.

Silica-containing shaped articles and a process for their preparation

A process for the preparation of a trichlorobenzene by chlorination of o-dichlorobenzene in the presence of a catalyst is disclosed. The catalyst comprises aluminum chloride. Preferably an iron or iron chloride containing aluminum chloride catalyst is employed.

Process for the preparation of trichlorobenzenes

Technically pure 2,4-diisocyanatotoluene or an isomer mixture having an increased 2,4-diisocyanatotoluene content is obtained from an isomer mixture of 2,4- and 2,6-diisocyanatotoluene. The 2,4- and 2,6-diisocyanatotoluene mixture is first cooled to a temperature of from 4.degree. to 9.degree. C. and further cooled to between -2.degree. to -6.degree. C. at a rate of 0.5.degree. to 3.degree. C. per hour. The temperature of the mixture is maintained at that temperature for at least 30 minutes. Any liquid present is removed and the solid remaining is then melted. Melting is preferably carried out by heating the solid at a rate of 0.5.degree. to 3.degree. C. per hour until the remaining solid has a 2,4-diisocyanatotoluene content of at least 98%. The liquid melt is removed and the solid having the desired 2,4-diisocyanatotoluene content is then melted.

Process for separating technically pure 2,4-diisocyanatotoluene or

A process for the preparation of 2-chlor-4-nitrotoluene is disclosed by chlorination of 4-nitrotoluene in the presence of iodine. The resultant 2-chloro-4-nitrotoluene is a valuable intermediate for the preparation of herbicides.

Process for the preparation of 2-chloro-4-nitrotoluene

A process for separating ortho-, meta-, and/or para-dichlorobenzene from an isomeric mixture thereof which comprises:

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Leverkusen, Germany

Adolf Wissner