Abstract: A method of measurement for analytical ultracentrifuges with a multi-cell rotor and with simultaneous measurement of several cells, in which light pulses of constant energy are passed, independently of the rotor speed, through individual selectable measuring cells in the entire speed range and in which these light pulses can be provided either by a controlled laser beam or a controlled Kerr cell or a controlled gas discharge lamp.

Abstract: The cartridge arrangement of the present invention enables recording and/or playback apparatus to be used with cartridges of various sizes, the cartridges being provided with releasable locking means and, after the release of such means, being able to be opened to permit the tape roll(s) to be rotated on the recording and/or playback apparatus.The cartridge arrangement is applicable to every type of recording medium in tape or strip form in systems employing cartridges in which there is a need for using cartridges of various sizes, especially in the case of the recording and playback of magnetic signals.

Abstract: The invention relates to an improved apparatus for the manufacture of magnetic discs carrying very thin magnetic layers, by applying a fluid dispersion of magnetic materials in a binder mixture to rigid base discs by the spin-coating process. Above the side of the base disc which is to be provided with the magnetic layer, there are arranged means which produce an aerodynamic boundary layer above the discs during rotation of the latter. This avoids the formation of surface irregularities and of coating streaks during production of the layer by spin-coating.

Abstract: A process and apparatus for the manufacture of magnetic recording media, in which, immediately before the magnetic dispersion is applied to a base, the dispersion is subjected to shear by means of a disc rotatably mounted in a housing, by introducing it at the center of rotation of the disc and forcing it through a gap formed between the face of the disc and the wall of the housing, which gap tapers toward the rim of the disc.

Abstract: Azo dyes which in the form of the free bases correspond to the general formula ##STR1## where R.sup.1 is hydrogen, chlorine, bromine, methyl, trifluoromethyl, methoxy, nitro or a radical X, R.sup.2 is hydrogen, chlorine or nitro, R.sup.3 is hydrogen, chlorine, bromine, methyl, methoxy, nitro or a radical X, R.sup.4 is hydrogen or alkyl of 1 to 3 carbon atoms, R.sup.5 is cyano, carbamoyl or acetyl, R.sup.6 is hydrogen, substituted or unsubstituted alkyl or cycloalkyl or a radical X and X is a radical containing an amino group, the molecule containing at least one radical X. The compounds of the formula I are exceptionally useful for improving the flow of pigment-containing printing inks.

Abstract: Polyethers are manufactured by polycondensing about equivalent amounts of a bisphenol and of a dihalogen compound in the presence of an anhydrous alkali metal carbonate, in the absence of a solvent or diluent. The polyethers may be used for the manufacture of moldings, fibers, films, adhesives and coating compositions.

Abstract: Iodine-containing block copolymers which contain from 5 to 25% by weight of bonded iodine, and which are based on iodine-free compounds of the formula IR(AB).sub.z Iwhereif z=1, R is hydrogen or a C.sub.1 -C.sub.18 -aliphatic hydrocarbon radical,if z.noteq.1, R is a z-valent aliphatic hydrocarbon radical of 2 to 8 carbon atoms, which may or may not carry up to z ethylene oxide units,z is from 1 to 6,A is a polymer or copolymer block of from 4 to 100 1,4-butylene oxide units and from 0 to 25 ethylene oxide units andB is a polymer or copolymer block of from 0 to 50 1,4-butylene oxide units and from 1 to 100 ethylene oxide units, the proportion of 1,4-butylene oxide being >50 mole % in A and <50 mole % in B.

Abstract: Thermoplastic molding compositions based on rubber-modified styrene-acrylonitrile copolymers containing a halogenated styrene oligomer as the effective flame-proofing agent which is sufficiently heat-stable, does not interfere with processing on conventional machinery, does not corrode or cause coatings on such machinery, and has virtually no adverse effect on the impact strength of the polymers. The flameproofing agent as a rule has a degree of polymerization of from 3 to 200 and can be incorporated into the polymer by conventional methods; the polymer may or may not contain additional synergistic agents and processing auxiliaries, which are incorporated in the conventional manner and in the conventional amounts.

Abstract: A process for the preparation of PVP-iodine by reacting polyvinylpyrrolidone powder with elementary iodine at from 70.degree. to 100.degree. C. The reaction is carried out in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid. The process avoids the disadvantage of long periods of heating, which can result in degradation of the polyvinylpyrrolidone, and is particularly suitable for the preparation of a stable PVP-iodine using a low molecular weight polyvinylpyrrolidone.

Abstract: A flexible multilayer magnetic recording medium exhibiting an improved signal-to-print-through ratio coupled with an improved maximum output level and diminished dc noise, comprising a non-magnetic base and, applied thereto, at least two superposed layers consisting of a binder with magnetizable particles uniformly dispersed therein, the upper magnetic layer containing a magnetic pigment giving a signal-to-print-through ratio of less than 55db and the lower magnetic layer(s) containing a magnetic pigment giving a signal-to-print-through ratio of 55 db or more.

Abstract: Polyethers, preferably containing sulfone groups, are obtained by a multi-stage condensation process at from 100.degree. to 230.degree. C. from substantially equivalent amounts of bis-(4-hydroxyphenyl)-sulfone and a dichlorobenzene compound in a polar aprotic solvent in the presence of an anhydrous alkali metal carbonate, with or without the addition of a compound which forms an azeotrope.

Abstract: A process for the preparation of .alpha.-hydroxy-.beta.,.beta.-dimethyl-.gamma.-butyrolactone (pantolactone) by condensation of formaldehyde with isobutyraldehyde to give hydroxypivalaldehyde, conversion of the latter to its cyanohydrin, and subsequent acid hydrolysis and lactonization, wherein formaldehyde and butyraldehyde are reacted in the presence of a tertiary amine, hydrocyanic acid, at a concentration not exceeding 1% by weight in the reaction mixture, is used to form the cyanohydrin, and the hydrolysis and simultaneous lactonization are carried out with gaseous hydrogen chloride.

Abstract: An improved process for the preparation of hydroxycitronellol by an addition reaction of water with citronellol. This reaction takes place directly on heating a homogeneous solution of citronellol in a mixture of water and an .alpha.-methyl-branched lower alkanol in the presence of a strongly acid ion exchanger.Hydroxycitronellol may be used as a fragrance material and is an important intermediate for the preparation of the highly desired scent hydroxycitronellal.

Abstract: A process for the preparation of 1-cyano-2,1,3-benzothiadiazinone compounds by reacting a mixture of bromine and water with an inorganic cyanide and then with a salt of a 2,1,3-benzothiadiazin-4-one-2,2-dioxide and a base.

Abstract: Complementary circuits for pre-emphasis and de-emphasis of video luminance signals, the circuits permitting an improved signal-to-noise ratio in a video signal transfer channel. The video signal has separate frequency- and amplitude-sensitive portions as well as a linear gain portion, thereby providing a fixed gain up to a predetermined lower frequency, a fixed response between this frequency and a variable upper frequency breakpoint, and an amplitude-dependent gain above the upper frequency breakpoint. De-emphasis is performed by a circuit also having separate frequency- and amplitude-sensitive portions and a linear gain portion, and which may be readily matched to the pre-emphasis circuit.

Abstract: Silicate fouling on the reboilers and trays and the distillation train used for the production of dihydric alcohols is arrested by the addition of caustic to the feed stream.

Abstract: Highly stable liquid 4,4'-diphenylmethane diisocyanate (MDI) containing MDI-carbodiimide adducts are prepared by heating MDI at a temperature of from 180.degree. C. to 250.degree. C. for a period of from one hour to ten hours in the presence of tris(chloromethyl)phosphine oxide and thereafter equilibrating the adduct formation. Equilibration can occur by any of several methods, i.e., by cooling the composition to a temperature of from 60.degree. C. to 90.degree. C. within twenty minutes, maintaining the composition at this temperature for a period of from one hour to four hours and thereafter cooling the composition to room temperature or by cooling the composition to a temperature less than 100.degree. C. within twenty minutes, further cooling to room temperature, and maintaining the composition at room temperature for one week to two weeks. The resulting compositions have very low sediment contents and are particularly useful in the preparation of microcellular polyurethane foams.

Abstract: Lubricants and processing aids for thermoplastic synthetic fibers, particularly polyester and nylon fibers are disclosed together with processes therefor. Said lubricants comprise compounds having the structural formula: ##STR1## in which R and R.sub.1 are independently selected from straight or branched chain aliphatic radicals having about 7 to about 22 carbon atoms; A is oxyethylene or a heteric mixture of oxyethylene and oxypropylene residues derived from the reaction of ethylene oxide and 1,2-propylene oxide in the respective ratio by weight of about 3:7 to about 9:1; and n has a value to produce a compound having a molecular weight of about 300 to about 3000. Said compounds are the ethoxylated or alkoxylated reaction product of the reaction product of an alpha-olefin epoxide and a fatty alcohol.

Abstract: Method of cataphoretically coating the surfaces of electrically conducting substrates acting as cathodes in an electrical lacquering bath based on aqueous solutions and/or aqueous dispersions of salts of cationic film forming agents with organic and/or inorganic acids wherein the coating bath contains chloride ions dissolved therein with nitrate ions, nitrite ions, or a mixture of nitrate and nitrite ions in a weight ratio from about 0.01 to 8 parts of chloride ions to 1 part of nitrate ions, nitrite ions, or a mixture of nitrate and nitrite ions.

Abstract: A process for making alkali hydroxide and chlorine in a plurality of electrolytic cells of the amalgam type, wherein a decomposer is provided for each cell and wherein alkali metal amalgam formed in the cell is reacted with water in a companion decomposer to form alkali hydroxide, the improvement comprising utilizing for each cell and corresponding decomposer a condenser and a separator component between the condenser and decomposer in the hydrogen outlet line of the decomposer to separate mercury vapor and water vapor initially liquefied in the condenser and divert the condensed mercury back into the decomposer.