Abstract: In a process for the recovery of a polymerizable useful fraction, consisting of styrene, methylstyrenes, vinyltoluenes, indene, methylindenes and fractions whose boiling points are between styrene and methylindenes, from the crack gases of a steam cracker, the sidestream of the crack gas column is divided, by means of a distillation unit, into the useful fraction and into fractions which are recycled to the crack gas column.

Abstract: In an electrode suitable for electrolysis of aqueous sodium chloride or potassium chloride solutions, at least the outer layer contains spinels, specifically a mixture of the individual spinels of iron and of cobalt, the weight ratio of iron spinels: cobalt spinels being from 30:70 to 90:10.The electrodes are produced by applying a powder mixture of iron spinel and cobalt spinel to a substrate by a plasma spraying process wherein argon is used as the plasma gas and the spraying energy is from 6 to 30 kW.

Abstract: A process for the manufacture of wear-resistant magnetic recording media comprising a dimensionally stable base, a thin ferromagnetic metal layer, containing cobalt and/or nickel, firmly bonded thereto and a thin protective layer applied thereon. The protective layer is produced by treating the recording medium in a liquid basic medium, containing gaseous oxygen, for from 1 to 60 minutes at from 5.degree. to 70.degree. C., washing and drying the treated recording medium and then heating it in air at from 170.degree. to 300.degree. C. This method offers a particularly simple way of providing the ferromagnetic layer of the recording medium with a thin but uniform, mechanically stable and wear-resistant protective layer.

Abstract: In a process for the manufacture of sodium dithionite by reacting sulfur dioxide with sodium formate and aqueous sodium hydroxide solution in the presence of methanol, an aqueous methanolic solution of sodium formate is first produced by reacting carbon monoxide with sodium hydroxide solution in an aqueous medium, containing from 1 to 50% by weight of methanol, based on the amount of water, at from 80 to 120.degree. C. under a pressure of from 10 to 40 bars. The resulting aqueous methanolic solution can be reacted directly, in the conventional manner, with sulfur dioxide and aqueous sodium hydroxide solution to give sodium dithionite.

Abstract: In an electrolysis cell with anodes and cathodes which are provided with openings, the cathode chamber is separated from the anode chamber by a diaphragm. The latter consists of a porous layer of oxides or oxidic compounds of the elements of sub-group 4B of the periodic table, of aluminum, of the rare earths or of chromium. The diaphragm is applied to that side of one of the electrodes which faces the counter-electrode.

Abstract: Manufacture of electrodes consisting of bases of valve metals with electrochemically active coatings applied thereto. The electrodes are pre-treated before the said coatings are applied, the pre-treatment comprising treating the base with hydrogen.

Abstract: Finely divided metal oxides produced by combustion of metal carbonyls are separated from the stream of gas by filtration. Before filtration, the stream of gas is subjected to a permanent change of direction in a tubular zone. This change of direction must be sufficient to cause a centrifugal acceleration which is from at least 1,000 to 10,000 times the acceleration due to gravity.

Abstract: A process for the manufacture of rigid magnetic recording media by depositing a cobalt-containing ferromagnetic metal layer on a non-magnetic metallic base disc provided with a cured layer of binder which does not dissolve or swell in organic solvents and contains non-magnetic pigments, and which has been activated, before deposition of the ferromagnetic layer, by treatment with a solution of a palladium (O) complex in an organic solvent, followed by decomposition of this complex, to prepare it to receive the ferromagnetic metal layer which is produced by electroless deposition.

Abstract: An accumulator having an acid electrolyte and possessing two electrodes of the first kind mounted on base electrodes. The active material on the positive side contains manganese dioxide. The base electrode on the negative side consists of powdered graphite embedded in a binder which is resistant to the electrolyte. The base electrode on the positive side has a coarse porous structure and consists of graphite or titanium coated with titanium nitride or titanium carbide. The average pore diameters are from 0.1 to 2 mm and the pore volume is from 20 to 70%.

Abstract: Accumulators having solution electrodes containing manganese dioxide and lead dioxide as active material on the cathode side and containing acid electrolytes. The electrolyte has a content of onium salts soluble in aqueous medium.

Abstract: A method of stabilizing pyrophoric metal powders by treating the metal powders with alkylene oxides to form a polymer coating on the metal particles.

Abstract: A process for the manufacture of acicular gamma-iron(III) oxide, in which the non-magnetic, acicular iron(III) oxide is treated with a solution of a compound of the formula I ##STR1## where R.sup.1 and R.sup.2 are ##STR2## or O--R.sup.5, R.sup.3 is H, OH, ##STR3## or O--R.sup.5, R.sup.4 is alkyl or cycloalkyl of 1 to 16 carbon atoms and the R.sup.4 's may be identical or different, and R.sup.5 is alkyl, cycloalkyl or aralkyl of 3 to 18 carbon atoms, and is then converted to gamma-iron(III) oxide by reduction to magnetite, followed by oxidation.The gamma-iron(III) oxide obtained is distinguished by a high coercive force and improved magnetic orientation when used as a magnetic pigment for the manufacture of magnetic recording media.

Abstract: An anode for electrochemical processes consists of an electrode base plate of a metal which can be passivated electrochemically, a protective layer deposited thereon, and a further layer, consisting of manganese dioxide. The protective layer consists of the nitride of the metal of the electrode base plate.

Abstract: A process for the manufacture of acicular ferromagnetic metal pigments containing iron, having a reduced field strength distribution and a steeper residual magnetization curve, by applying equivalent amounts of an alkaline earth metal cation and of a monobasic, dibasic or tribasic aliphatic carboxylic acid of up to 6 carbon atoms onto appropriate acicular iron oxides and then reducing the treated oxides.

Abstract: A process for the manufacture of acicular magnetic gamma-iron(III) oxide by reducing acicular alpha-iron(III) oxide to magnetite and then oxidizing it to gamma-iron(III) oxide, wherein the alpha-iron(III) oxide is treated with a water-soluble alkaline earth metal compound and an alkylphenol with one to three alkyl radicals, each of 4 to 24 carbon atoms, on the benzene nucleus. Gamma-iron(III) oxides manufactured in this way show better magnetic orientability in the binder-containing dispersion, and a higher coercive force than prior art magnetic pigments.

Abstract: Magnetic recording tape especially suitable for use as video tape and computer tape, comprising a base carrying a magnetic coating which consists essentially of a dispersion of a finely divided magnetic pigment and at least one lubricant in an organic binder. The lubricant is a compound of the formula ##STR1## IN WHICH N IS AN INTEGER OF FROM 3 TO 8 AND R.sup.1 and R.sup.2 are an alkoxy or aralkoxy radical or conjointly are an alkyldioxy radical of 3 to 18 carbon atoms. A magnetic recording tape prepared with a high proportion of such a lubricant is distinguished by high abrasion resistance coupled with a minimum transfer of material to the magnetic heads even under fluctuating climatic conditions.

Abstract: For the preparation of anhydrous sodium dithionite by the reaction of sulfur dioxide with sodium formate and caustic soda in the presence of organic solvents, sulfur dioxide is passed, together with the formate, into a liquid containing all of the caustic soda required for the reaction. This initial liquid may contain, in addition to the caustic soda, a portion of the sulfur dioxide or formate required for the reaction.

Abstract: A process for the manufacture of acicular ferromagnetic metal pigments containing iron, having a reduced field strength distribution and a steeper residual magnetization curve, by applying an alkaline earth metal cation and an organic compound having at least one group capable of forming a chelate to appropriate acicular iron oxides and then reducing the treated oxides.

Abstract: New and valuable substituted fluorophosphazenes, pesticides containing these compounds, and a process for controlling pests with these compounds.

Abstract: A process for metallizing substrates by activation of the substrate by deposition of palladium from a palladium complex, followed by electroless metallization. The palladium is deposited on the substrate by dipping the substrate into a solution of a palladium(O) complex and decomposing this complex at from 100.degree. to 300.degree. C.With this method it is possible to effectively activate substrates which are attacked by acid or alkali or swollen by organic solvents.