Bayer Aktiengesellschaft

Johann-Nikolaus Meussdoerffer

Hans Niederprum

Wolfgang Bockelmann

Karl-Heinz Mitschke

Paul Vente

Hans-Georg Nieder-Vahrenholz

Heinz Gunter Klein

Hans-George Nieder-Vahrenholz

A process for the manufacture of injection molded articles out of material that is capable of being processed in an injection molding process comprising injection fluid material into a hollow space of a mold of a desired form, hardening or reacting the injected material at raised temperatures and subsequently separating the molded article from the mold at the same high tempeature by the aid of inert gas and/or air, pressed between the molded article and the mold, which is regulated by a self readjusting conical valve.

Process for the manufacture and separation from the mold of injection

In the disintegration of a chromite or chromium-containing residue, wherein the chromium-containing material is disintegrated with an alkaline compound in the presence of oxygen and a diluent at a temperature above about 800.degree. C. and thereafter leached, the improvement which comprises pre-roasting the chromium-containing material prior to addition of the alkaline compound. Pre-roasting can be effected at 400.degree. to 1200.degree. C. with addition of certain amounts of silica dioxide and/or aluminum oxide and such additives, depending on the chromium containing material, if still required, are added--prior to disintegration and leaching--in such a quantity to establish a ratio of SiO.sub.2 : AL.sub.2 O.sub.3 of about 2:1 and further a ratio, calculated on the basis of NaOH as the alkaline compound, of SiO.sub.2 : Na.sub.2 O of about 1:0.5 plus a Cr.sub.2 O.sub.3 : Na.sub.2 O ratio of about 1:2 to 1:4. Residues from previous leaching cycles can be present during disintegration as solid diluents but their contents of SiO.sub.2 and/or Al.sub.2 O.sub.3 are not taken into account in calculating the SiO.sub.2 :AL.sub.2 O.sub.3 ratios. The process gives excellent results even with starting materials relatively high in SiO.sub.2 which are difficult to disintegrate to materials of desirable properties by other methods.

Disintegration of chromites

Production of tetraethyl ammonium perfluoroalkyl sulphonates (C.sub.2 H.sub.5).sub.4 N.sym.R.sub.F SO.sub.3 .crclbar., wherein R.sub.F represents a perfluorinated alkyl radical with about 4 to 10 carbon atoms, by reacting crude perfluoroalkyl sulphonic acid fluoride, i.e. perfluoroalkyl sulphonic acid fluoride which has not been especially purified, with triethylamine and an ethoxy silane, preferably dimethyl diethoxy silane, methyl triethoxy silane or tetraethoxy silane in an inert solvent at temperatures of about 10.degree. to 60.degree. C., preferably about 20.degree. to 40.degree. C. The process according to the invention is particularly suitable for the production of tetraethyl ammonium perfluorooctane sulphonate.

Production of tetraethyl ammonium perfluoroalkyl sulphonate

In the disintegration of at least one chromium source selected from the group consisting of a SiO.sub.2 -containing chromite and a chromium-containing residue with an alkali compound at a temperature above about 800.degree. C in the presence of atmospheric oxygen and a lime-free diluent, followed by leaching of the mixture with at least one of water and/or a chromium (VI)-containing aqueous solution, the improvement which comprises including in the mixture to be disintegrated an aluminum compound and at least sufficient alkali to form alkali chromate and to convert the SiO.sub.2 into an alkali-aluminum silicate corresponding to the formula nMe.sub.2 O . mSiO.sub.2 . Al.sub.2 O.sub.3, wherein Me is at least one of sodium and potassium, 0.8 .ltoreq. n .ltoreq. 1.2 and 1.3 .ltoreq. m .ltoreq. 4.3.

Disintegration of silica-rich chromite

In the etching of glass wherein glass is contacted with an aqueous etching bath containing hydrofluoric acid, and the glass is thereafter removed from the bath and rinsed, the improvement which comprises dissolving in the etching bath an acid-resistant wetting agent. Preferably the wetting agent contains fluorine, e.g. a perfluoralkane sulfonic acid quaternary ammonium salt, a perfluoralkane carboxylic acid salt, an alkoxylation product of a perfluoralkane sulfonamide, or the like.

Growing community of inventors

Leverkusen, Germany

Johann-Nikolaus Meussdoerffer