Abstract: A process for preparing acrylic acid and/or acrylates, which comprises stage A with or without stages B and C: A: cooling a gaseous reaction mixture which comprises acrylic acid and is obtained in the gas-phase oxidation to prepare acrylic acid, using an inert high-boiling solvent, to give a gaseous mixture comprising acrylic acid; B: separating the gaseous mixture comprising acrylic acid to give a low-boiling fraction, a crude acrylic acid, and a bottom product, and C: esterifying the crude acrylic acid obtained in stage B by means of one or more alkanols to give an esterification mixture comprising one or more acrylates and one or more acetic esters.

Abstract: In a process for stabilizing chemical compounds having at least one ethylenically unsaturated bond to undesired free radical polymerization, a nitroxyl radical and a chemical compound containing phosphorus in chemically bonded form are added to the unsaturated compound present as pure substance or as a component of a mixture.

Abstract: Free radical polymerizations immediately terminated by a process comprising the addition of an inhibitor solution which contains phenothiazine and at least 50% (w/w) N-alkylpyrrolidone to a system undergoing free radical polymerization, wherein the inhibitor solution also contains p-methoxyphenol (MEHQ).

Abstract: The process for the esterification of (meth)acrylic acid with an alkanol in the presence of an esterification catalyst, in which unconverted starting compounds and the (meth)acrylate to be formed are separated off by distillation and an oxyester-containing bottom product is formed and is separated off, and (a) in the bottom product separated off, the oxyesters present are cleaved, if required after the addition of (meth)acrylic acid and/or oligomeric (meth)acrylic acid, directly in the presence of acid catalysts differing from (meth)acrylic acid and/or oligomeric (meth)acrylic acid, and the cleavage products are removed, a cleavage residue remaining, or (b) the oxyesters are first removed by distillation from the cleavage product separated off, a distillation residue remaining, and the oxyesters removed are cleaved, if required after addition of (meth)acrylic acid and/or oligomeric (meth)acrylic acid, in the presence of acid catalysts differing from (meth)acrylic acid and/or oligomeric (meth)acrylic acid, a

Abstract: An arrangement is provided for digital transmission of information via lines between a line termination (1) of a telecommunication network and subscribers (Tln) connected to the line termination. At least one terminal of a subscriber (Tln) is connected to a network termination (2) via an electric line (L3). The network termination (2) is connected to the line termination (1) via a line (L2) having metallic conductors. The line termination (1) has a voltage source (SV) for supplying power to itself and to the network termination (2) and the subscriber (Tln) terminals. For increased reliability during operation, two separate power supply units (SVE1, SVE2) are arranged in the network termination (2). One of the two separate power supply units (SVE1, SVE2) powers active components of the network termination (2) and the other of the two separate power supply units (SVE1, SVE2) powers the subscriber (Tln) terminals.

Abstract: In a process for the preparation of acrylic acid, a product gas mixture obtained by catalytic gas-phase oxidation of a C3-precursor of acrylic acid and containing acrylic acid is directly cooled with a quench liquid and then subjected to fractional condensation in a separation column provided with baffles, said product gas mixture ascending into itself and a crude acrylic acid being removed via a side take-off, and the acrylic acid oligomers formed are cleaved and recycled.

Abstract: An article having a metallic surface treated with polymeric complexing agent is described. Particularly suitable polymeric complexing agents are phosphonoalkylated polyethyleneimines and/or carboxyalkylated polyethyleneimines and/or vinylimidazole polymers. As a rule, the treated metallic surface forms the total inner surface or a part of the inner surface of a process apparatus or of a container. The surface is protected by the treatment, in particular from the adhesion of polymer.

Abstract: An inhibitor mixture containing, as components, a) at least one nitroxyl radical (derivative), b) at least one phenol (derivative) and c) at least one chemical compound which contains at least one phosphorus atom which has the oxidation state +3 is preferably used for stabilizing compounds capable of free radical polymerization.

Abstract: Pure acrylic acid is stored and/or transported by a process in which the pure acrylic acid is stored and/or transported as liquid aqueous solution at ≦15° C.

Abstract: A process for the continuous recovery of (meth)acrylic acid from a liquid starting mixture containing (meth)acrylic acid, a high-boiling organic solvent and low boilers, medium boilers and high boilers is proposed, the mixture being separated into a first part-stream (a), which, in addition to (meth)acrylic acid, contains the low boilers and a part each of the medium boilers and high boilers, and a second part-stream (b), which contains the predominant part of the (meth)acrylic acid and is completely or virtually completely free of low boilers, and the (meth)acrylic acid being recovered from the part-stream (b).

Abstract: A method for continuous production of (meth)acrylic alkyl esters by reacting (meth)acrylic acid with alkanols containing 1-8 C-atoms, whereby raw (meth)acrylic acid containing acetic acid is used as a starting compound and the alkyl acetate that is formed as a by-product is evacuated in an appropriate area.

Abstract: Substance mixtures comprising (A) vinyl-containing compounds, (B) an active amount of a mixture inhibiting the premature polymerization of the vinyl-containing compounds, comprising (i) at least one N-oxyl compound of a secondary amine which carries no hydrogen atoms on the &agr;-C atoms, and (ii) at least one iron compound, (C) if appropriate nitro compounds, and (D) if appropriate costabilizers, a process for inhibiting the premature polymerization of vinyl-containing compounds (A) and the use of mixture (B), if appropriate as a mixture with nitro compounds (C) and/or costabilizers (D), for inhibiting the premature polymerization of free radical polymerizable compounds and for stabilizing organic materials against the damaging action of free radicals.

Abstract: A process for the preparation of unsaturated cyclic ethers of the general formula I ##STR1## in which Z denotes --(CHR.sup.4).sub.q or --(CHR.sup.4).sub.q --O--q is 0, 1, 2 or 3 andR.sup.1, R.sup.2, R.sup.3, and R.sup.4 denote hydrogen or C.sub.1 -C.sub.4 alkyl from diols of the general formula II ##STR2## in which, R.sup.1, R.sup.2, and R.sup.3 have the aforementioned meanings, in the presence of a cobalt-containing supported catalyst, wherein the cobalt-containing supported catalyst used contains cobalt and a noble metal--selected from the group consisting of platinum, palladium, rhodium, iridium, ruthenium, osmium, rhenium, or mixtures thereof--in an atomic ratio of from 0.5:1 to 70000:1 on an inert support and optionally basic alkali metal and alkaline earth metal salts, scandium, vanadium, chromium, manganese, iron, nickel, copper, zinc, germanium, tin, lead, antimony, bismuth, or mixtures thereof and the reaction is carried out in the liquid phase at temperatures ranging from 150.degree. to 300.degree.